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Oh my. God yeah you're important opening Z Hood Hello everybody good day to you! Welcome back! This is a Nissan Pathfinder I forgot the Year We're gonna check on that. customer states that uh is stalling and running rough and uh, misfiring things that nature. So uh, let's go ahead and get this into the shop.

Let us connect our diagnostic devices. Yeah, what do we got here? 1999 99 Pathfinder Let's get it in the shop. connect our scan tools, see if we have trouble codes. We'll take a look at the engine, see what's going on here.

Rough start too. 272 1075 miles on the clock. Yeah, we're getting up there with this thing. Pretty clean though.

Nice. There it is. There's that old money light. yeah it feels rough like even just right here in the parking lot.

Moving on in around the corner of death, our steering pump I was hard over on the on the steering wheel. That was belt slippage. good. Nuzzle you in right about here.

I'd say that's good. Parking is the auto and popping's your hood. All right. Let's see what we got going on here.

Okay, we're looking like a 3.3 liter. V6 Here someone has put uh, looks like spark plug wires. a cap wraps a whole distributor that looks kind of new. Yeah this distributor has been replaced.

It looks like okay I wonder what is wrong I wonder what it could be All right? Scan tool coming in. Let's take a look at our trouble codes. let's see what's going on here. Oh scan tool powering on.

Beep right there. Okay, all right, we're going into scanner. We're finding Nissan dots and where are you? Dotson there we are. Automatic I think this is too old for Auto ID Waiting waiting.

It's not gonna do it. Canceling waiting on canceling. Okay, we're in. Had to manually input.

uh. automatic transmission with air conditioning. Use the Nissan adapter key I don't have any Sun adapter cable. We're just going to skip that.

The I hope that doesn't turn into a hindering Factor What? No communication. That's not good. We don't want that here. We uh, went ahead and backed out a Nissan specific and I went into a global OBD Let's see if I can talk to it like that.

Come on. Okay, it has detected one. ECU Continue Continue with global protocol. Please continue.

Okay, we want to display trouble codes. Let's go into that. Okay, here we go. We've got a P300 random slash multiple cylinder misfire detected That's fairly generic.

It's just saying that we found a misfire. Then we've got a P0174 fuel trim system lean. Bank Two: we are lean. Oh, next challenge, we got codes.

Can we get data I Want to see some live data? Fingers crossed. Give us data please. Still collecting. Oh oh, we've got some live data.

This is good. Now there's our mass airflow. 5.97 grams per second. That's okay.

Pressures There we go. Here's the fuel trim action. Short terms: Doesn't tell me which bank it is yet? Long term: I'm assuming that's bank one and then down here is Bank two. So we've got positive 20 Short Terms on Bank Two: Yeah, there it is.
Field Trim Bank Two and we have negatives on Bank one. So one says one thing, the other says another thing. What is going on here? Check some O2 voltages. Let's make sure these are switching.

Okay, here's our O2 Bank One Let's give it some throttle. Here we're looking at our top graph. What we want to see is this thing: switching high low high low high low. It looks like Bank One is not what is Uh Bank two.

Doing it is sensing the oxygen levels uh in the exhaust stream and the ECM is constantly trying to uh manage the fuel Curves in order to reach an optimal air fuel ratio. So you know we see this one's not doing anything either. It's not switching I Wonder if I can reset fuel trims? Let's just see if I can reset fuel trims? Those O2 sensors should just start doing what uh, what they would do normally and we could monitor them at that point to see if one of them is hanging up The most clear data. blah blah blah Well, we know what the codes are.

We know what the symptom is. We know that fuel trims are rich on one side. lean on another side. So I'm going to go ahead and clear everything out and we're going to go back and revisit.

the O2 sensor data Okie Dokes All the diagnostic data has been cleared. That should mean that field trims have been cleared. Let's go back and display that data one more time. You know your car is well loved when it's spotless at 300 000 miles and 25 years old and it's got a thumb Notch worn into it.

Let's find those O2 sensors one more time. See how short tent, short trim short term that's reset to zero. All this fuel Trends are nearing zero. So let's watch those oxygen sensors.

There's Bank One There's Bank two. Let's see which one of them is not happy. Let's go into graph. We're going to do a two graph and we want to do O2 sensor Bank two: The Bank 102 sensor is still not switching very well.

That's I Don't like what we're doing here because we shouldn't have it stepping up and down. We should just be going up and down. up and down. Scroll down to this one that Sensor 2 on bank one.

This one's monitoring the cat converter. This one's not really switching either I wonder if I can unplug these? Let's see what fuel trims do. Okay, here we go: I Switched this to a two graph and I just selected the Bank One Sensor One voltage and Bank two Sensor One voltage. These are the pre-cat O2 sensors.

These are the ones that the ECM uses to determine how much fuel to give each Bank of cylinders. So you've got bank one which is like cylinder one, three, five, and Bank two which is going to be like two, four, and six. Looks like our O2 sensor are Upstream Bank 2 Sensor one just died on us. The Bank 1 sensor.

it is switching. It's kind of sloppy. This may be a result of the fuel trims being completely 180 opposite directions because one side's running rich and one side's running lean so this may be affected by that. But it does look like our our O2 sensor on bank 2 has died out.
So we've got Bank two sensor one. Again, that's pre-cat no volts. It seems to be dead, so that doesn't mean the sensor died. It may have a power supply or some other issue.

Let's go ahead and pull up some service data and uh, maybe we can take a look at what supplies power to that Upstream O2 sensor. Okay, we can even see it here on the pit list. zero volts. So it's just gone in a closed loop and now all of a sudden fuel trims are getting.

uh, they're going into the negative here on Bank One. But we're also in the positive here on Bank two 25 and negative 25. So these things are running opposite of each other. See if uh voltage came back for that? Uh, Bank two Upstream could have zero volts.

Okay, I'm looking at the service data and I've got the diagram for both of the front oxygen sensors pulled up. We've got left front and right front right here and I'm reluctant to believe it's a power supply issue because they also share power at this 25 amp fuse right here coming out of the fuse block. So they share a power fuse which is going to be bear with me here. Let's unhighlight this.

this right here is power supply to both O2s. So I don't believe we have a power supply issue because the Bank 1 sensor is operating. We've got com lines to our ECM on bank one and Bank two and then we have our grounding circuit. That's this one here.

I Think this is grounding. Okay, that goes to uh oh that passes through the firewall at a grommet. I Think that's just all grounds. Yeah, these are these look like grounds NCAA love to read into that I don't know what NCA is I'm assuming those are grounds.

Hmm, Okay, well we know which one we're focusing on that's going to be Bank two Upstream we're still not getting voltage Let's Uh, let's go ahead and identify that uh, that sensor and uh, take a look at it and see what's going on. Okay, according to this graphic, if this is the front of the engine cylinders one, three, and five, that is the passenger side of the vehicle that's going to be bank one, cylinder, two, four, six, That's the driver's side of the vehicle That's going to be Bank two and it looks like Bank Two Sensor: One pre-cat on the exhaust is our affected sensor. Let's go ahead and visually inspect it, and if it's easy enough, we'll pull it out and take a look at the sensing device inside of it. So let us power this thing down.

Look at here. now. there's voltage on the circuit. See that.

Hang on. restarting. No communication, blah blah yeah. Go back to where you were all right.

I Did see a little bit of voltage on that circuit. It did switch a little bit. Let's go ahead and pull it out and take a look at it. three.
Powering down, there's more voltage engine off than there is engine on. Look at that now. unfortunately for me, the Bank 2 Upstream is the sensor that is under the intake. Here we can.

We can see it way down yonder, kind of far away. if someone replaced that before. It looks kind of newish-ish Yeah, that is newish. Ish I Can see the white on the sensor.

Hmm, it runs up and over. Looks like it connects over. here. There's our connector.

Okay, okay, here's the connector for the Bank two. This right here is connected for Bank One Uh, I Think those are the correct ones. Let me retrace these one more time. Well, seeing as how this thing has one, two, three, four new sensors on it that makes this horse a different color, doesn't it? This is our Bank one.

I'm sorry Bank two Upstream Right here. These connectors look okay. that was the clip on that's broken but I don't think that's it because it was fully seated. This one right here.

this is, uh, the Bank One Upstream I wonder I wonder I wonder I'm gonna flip-flop these connectors. Is this gonna work? Yeah, as it is. See what? I've just done there I Just flip-flopped the connectors. So now the Bank One sensor is connected to the Bank 2 side of the harness.

The Bank 2 sensor is connected to the bank one side of the harness. Let's go revisit data and uh, see if this suspected faulty sensor shows up on the bank one side, we should see no voltage occurring. Basically what this is going to confirm or deny is if that sensor that's already there is faulty or not. it makes no difference to me whether it's new or it's not new.

We're just going through the process of diagnosing right now and seeing as how the swapping connectors was actually fairly easy I Just went ahead and did that. We'll call it a time saving strategy. Okay, data's back up. We're scrolling down we're looking for let's find Bank One Sensor One and Bank two Sensor One that's Bank One Sensor One Look, it's switched sides.

Oh, there's some voltage. We got voltage. again. Well look what we have here.

We are getting voltages on Bank One Sensor One and Bank Two Sensor One: There's voltage. There's voltage I Wonder if there was a poor connection at the actual connectors? Let's go switching back real quick and make sure we got a good, solid connection. That may be all that is. Uh, what's wrong with this car? Go inside the cabin.

We'll reset everything one more time. So this is the bank two side that's plugged in where it's supposed to be I Had it disconnected. the bank One side is now plugged in again where it's supposed to be. I'm almost starting to think there was a bad connection right here.

Let's go see what the data tells us now and again. Look at that. Bank Two Sensor one is still hovering around zero volts. You can't see it highlighted.

I Think two Sensor one is not working when it's plugged into where it's supposed to be. Let's go ahead and unplug the Bank One sensor and we should see that fall to near zero. I Know this is a lot of back and forth, but since these things are so easy to reach Bank One disconnected. so we should see zero volts or mirror zero volts on that PIN Is this? Hang on? Maybe there's a huge delay in the day to give it a second.
This thing was talking slow. Let's give it just a second. So I've still got bank one and Bank two sensors switched. they're plugged in and now they both seem to be online and fuel trims are coming back into play again.

I'm starting to just think that uh, we had a bad connection at that bank two sensor and it was dropping out and causing the thing to uh to go lean on on Bank two This is. this is a little odd. It doesn't uh, doesn't seem to make any sense I'm gonna go ahead and just switch those back to where they're supposed to be and then we're going to reset everything again and I'm going to remoditor it seem to be working now. it's like, like, sir, wasn't working earlier Dan Functioning wants to plug it into the connector for the other sensor.

So now that we've determined that the sensor, which is new, is capable of functioning, let's plug it back into where it goes. and uh, maybe we can just rule this out as a poor connection right here somewhere and we can take a look at those pins a little bit deeper. So let's head back into the cabin, revisit our data, and see if our fuel trims are stable or not. What do we got here and that's uh, what do we got? I Saw a negative number somewhere.

a big one, like negative 20 something. It's gone now here. I'm just gonna give this some some throttle and we'll hold it for a little while and we'll see what these, uh, short-term and long-term feel trims do. There we go.

Short term Bank Two went through the roof tank one. We're going negative again. What's going on here? Well, son of a biscuit I'm I'm getting frustrated here because I've got these two. Uh, I've got the two Upstream O2 sensors connected backwards.

So I've got the left side on the right side connector and the right side of the left side connector. I Cleared the fuel trims and now everything is operating exactly like it's supposed to be. Fuel trims are near zero. Look 1.6 for short term on Bank Two Negative: 1.4 for a short term on bank one.

Like that's that's all right where it should be. It's hovering right around zero and long terms are not trending I Don't understand because I I Plug these in backwards and everything is working like like it's supposed to be. What if? What if they were mixed up when they were replaced? I'm I wonder I really wonder I wonder if it just came in and we had the connectors flip flop from the get-go when those O2 sensors got to play got replaced originally because this is all exactly where it should be. But I Know that I crisscrossed those connectors.
These guys. This one was found right here and this one was found right here. but it seems to be quite possible to get the actual sensor connectors out of our way. A sensor connector goes there.

Let's get this one out of here. We can readdress that later. Yeah, here, let me shut this down. I I'm suspecting that all this stuff was, uh, somehow got crisscrossed my accident at one point.

Let's let's start over and uh, pretend I'm where where this was at one other point. So I've got everything disconnected. Let's say we just changed all the sensors. Here's our wiring harness.

I Found these two connectors connected here. These two connectors connected down there, right? You found a clue. Let's go with what we know. What we know is this: this thing right here is going to be critical.

We know that this goes right in here. See that now. these can't go over here because now there's not enough reach even if we route this on this side because they don't reach. So I think that these go here in here and I think that these two the longer ones go over here.

That's what I'm starting to think here. so let's wire this up as if this connector is going to go here on this side. Is that going to work? Yep, click q1 and then this one which is the downstream for Bank two. Let's say that one goes on this side, but we're not even going to connect that just yet.

Let's just connect the upstreams. So this looks like a downstream and this is our Upstream connect those and we'll go ahead and clip that on to the little bracket here. I Choose this one. Please go on to the little bracket.

There we go And then our Upstream sensor on bank 2, which is over there. We'll connect that one to the bracket as well. Do not make a liar out of me. Okay, so the only thing left unconnected is our Catalyst monitoring O2 sensors.

Those are the downstreams. We can deal with those later. Let's go back and restart this and to verify our data. Yeah, I'm starting to think this thing came in with the wires backwards.

Okay. Engine running again. Short-term Bank Two Field trim is looking good. Short-term Bank One Fuel Trim That one's still looking good.

They're hovering around zero. so let's see what the sensors are doing. Bank one has some voltage. Bank Two Yes, where's Bank Two Bank Two has some voltage.

Okay, I'm gonna run this for a moment at high idle and we're just gonna see what those fuel trims do. Short-term Bank One is switching high, low, high low. We're seeing a little bit of negative. A little bit of positive.

Same thing with Bank two. A little bit of negative. A little bit of positive. Long-term Bank One is steady 8.6 4.7 on Bank two.

Anything within the plus or minus 10 is of no consequence fake One Sensor has voltage that's switching Bank two sensor has voltage that is switching and Sensor 2 and Sensor 2 are both open circuits that are defaulting at 0.3 volts to make sure that these are on the correct side. So let's go ahead and unplug Bank one. We know what Bank One is. that's the passenger side.
Let's disconnect the Bank One sensor real quick and we should see that voltage drop Bank One Upstream Disconnected Now let's head back into the cabin, raise the idol again and we'll see that Bank One does not have any activity. Okay, O2 Sensor Bank one Volt: 0.3 That's what we've already determined to be our open circuit voltage that reads on the PID and then Bank two. Sensor One: We're still switching here. We're going high, low, high, low.

so that's a confirmed fix. It was disconnected or it was connected on the wrong sides. We have the harness side connectors in the wrong position. This connector was over here.

This connector is over here and the harness was rerouted this way so it would reach and we failed to plug in. What we know which is that little wiring harness securing, zip tie thing. Firm fix. No parts needed.

Now all we need to do is determine which of these connectors is for the uh, the downstream O2 sensors. I Believe it's self-explanatory but you never know. So let's plug in the bank 2 Downstream and then we'll confirm that it has activity scan tool. If if we have activity on the bank one side then then we know that this one is also switch.

How does this go? It goes like this: fairly certain that's in the right spot. so I'm just going to put it on a bracket I Don't know if I said bang two but this is the Bank One Sensor two that's Post Cap So let's see. look for activity on Bank One Sensor two O2 Voltage Bank One Sensor two point seven volts and O2 sensor bank 2 Sensor 2 which is still disconnected 0.3 volts. We're getting somewhere now.

this is this is confirmed fixed I think we got it. let's plug in this other side and then secure that wire and I believe that's off the road. so if you in right here and then we'll secure that back down on its little uh little clip thing. do I cannot see.

ah there's a flashlight. Come on guy. get on there. Oh man, my guy's gonna be so thrilled to find out he doesn't have to spend any money.

I mean he's gonna spend some money but we're not. Uh, we're not buying parts, No parts. Cannon Okay, these are connected where they're supposed to be. Let's go recheck our data just to confirm everything.

This is awesome and look at that. Okay, let's graph it. Yeah, all four of these. they're all four switching high Low high low.

Let's take a look at our four bar graph O2 Sensor voltage. Look at that. These are our down streams. These are our Upstreams right here.

Everybody's switching like they're supposed to. We you were getting into a negative feedback loop where it was sending a signal or it was getting information saying this site is Rich and this side is lean so it added Fuel and took away Fuel And then what it said is this side is even more rich and this side is even more lean. So it added Fuel and took away fuel until both fuel trims were maxed out on either side. Then the ECM couldn't try to compensate anymore and that's where we got into the running rough condition.
But the graph is Beautiful Everything is doing what it's supposed to be doing. That is. Uh, that's that. Like, we got a confirm fix here.

There's no parts necessary. Uh, simple error in installation things happen. Oh I Need to go back in. Let's go ahead and clear those codes one more time just in case any have been set.

Okay, we're not going to need any more under hood lumens. So uh, let me get this thing out of here and then we're gonna go out, hit the road and go on a quick test drive. 3.3 liter. All right.

Well, this scanner is clearing all of the uh, all the information and doing one more reset. We're gonna go ahead and back this thing out and go for a quick test drive. Make sure all of our numbers say whether or stay where they're supposed to stay and get pretty close right there. All right, hitting the road here.

it's feeling pretty smooth. Yeah, it's got a good Power Band There's no stalling, there's no sputtering, there's no misfires. Problem solved. It was a simple installation error.

The computer got all flippy floppy, didn't know what to do, it was getting incorrect signals from the incorrect side, and the actions it was trying to taking was the uh, the opposite of what it was trying to achieve. Still, glancing down at the scan tool on occasion, and our fuel trims are right in line. Long terms and short terms, everybody's hanging out and hovering near zero. This is a hundred percent win.

Super pleased with the results here. So uh, that being said, I'm gonna go ahead and oh my God yeah, you're important. Let me go ahead and close this video out right now. and I will do so by thanking each and every one of you for watching the city right here.

Uh, not that one. I was talking about me? No, just kidding. I'm not that self-deprecating Uh, but I would like to thank you again for watching this video. As always, hope you enjoyed this video.

If uh, you did, in fact, enjoy this video. Please feel free to let me know about that in the comment section down below. Let me know if you ever encountered something like this while trying to diagnose a problem. Or let Me know if you actually cause something like this while trying to repair a problem.

That should be a fun comment thread. So again and as always, thank you for watching and most importantly, do not forget to have yourselves a great day! See you guys later in! Nissan Datsun Okey dokey! Back at the shop, we just backed into a parking space, revisiting our fuel trims one more time. Long terms are hovering at zero. Short terms are doing what they should be.
No check engine light, no problem with the sensors, We're good to go. Car is parked powering down. Re-ending of: Pathfinder See you guys later.

99 thoughts on “Wrong data! ecm is killing it! nissan pathfinder 3.3l datsun?”
  1. Avataaar/Circle Created with python_avatars Richard Gordon says:

    Good detective work again.👍

  2. Avataaar/Circle Created with python_avatars Medkow74 says:

    Did this to my A/C unit. I changed a gas valve in my furnace out and put everything back together, furnace works great again, then comes summer. After a week or two it just doesn't seem the A/C is working quit right. Here because my UV light in my furnace discolored the the 24v wires on the PCB I switched the 1st and 2nd stage wiring for the compressors in the A/C unit. The board outside was so confused.

  3. Avataaar/Circle Created with python_avatars Adrienne Fraschetta says:

    Glad u figured it out !!!

  4. Avataaar/Circle Created with python_avatars James says:

    great video as always. as soon as it showed rich on one bank and lean on the other i suspected the sensors were switched between banks causing a feedback loop.
    given that both sensors plug up at a similar location, it looks like a pretty easy error to make, especially if one isn't tagging the plugs or replacing/reconnecting the sensors one at a time so mistakes like this cannot happen

  5. Avataaar/Circle Created with python_avatars James Reardon says:

    Good job mate!

  6. Avataaar/Circle Created with python_avatars Damion Richter says:

    you didnt connect em wrong when they replaced the sensor they mismatched plugs bro

  7. Avataaar/Circle Created with python_avatars wisemjk says:

    Hv you been watching Ivan?

  8. Avataaar/Circle Created with python_avatars Just Me says:

    I'll share a story, similar to this one but I'm an electrician and it was in my trade. Went to a customer on a fault complaint that the underfloor heating in the shower was getting really hot even tho they had the thermostat set to low. Well I didn't diagnose it at first because my work order just stated that I should replace the floor thermostat. The thermostat has a sensing bulb that goes in a tube that goes into the floor between the heating element, so it switches the floor heating on and off according to the actual temperature of the floor, not just the room.

    Well a few days later I get a recall and still doesn't work. I start to dig into it a bit more. There are two thermostats side by side, one for the shower floor and one for the sauna floor. I talk to the customer. They have recently had some carpentry work done and they moved the wall that has the thermostats about 20cm. It is a timber wall. After some measuring and stuff I came to the conclusion that the carpenter had mixed up the sensing bulb tubes. So the shower thermostat was sensing the sauna floor and vice versa. So when the sauna floor was cold, it turned on the shower floor heating. That of course made the sauna sensing bulb hot (because it was in the shower floor tube) and therefore did not turn on the sauna floor heating leaving the shower floor sensing bulb cold.

    Long story short: electric floor heating, two thermostats with floor sensing bulbs that got mixed up.

  9. Avataaar/Circle Created with python_avatars Toto555 says:

    Liked your straight into the project, without the intro better. But don't object.

  10. Avataaar/Circle Created with python_avatars Jason Hodges says:

    See a union brothers' sticker on the windshield.

  11. Avataaar/Circle Created with python_avatars alan dawson says:

    when you had the wiring diagram, why you not check the color codes for the signal wires in the harness?

  12. Avataaar/Circle Created with python_avatars Lewingjr says:

    Instead of the guess and by golly shouldn’t you have just looked at the wire colors on the harness against the wiring diagram you had up?

  13. Avataaar/Circle Created with python_avatars Oscar Bravo says:

    Looks like you're off the ground, sir. As always, the content is top-notch and full of great objective reasoning and critical thinking. Can you imagine if the customer had gone somewhere else? Two barrels of partshot!

  14. Avataaar/Circle Created with python_avatars woodwerkman1 says:

    Looks like your keeping plenty work Ray. Good for you especially vas a startup repair shop

  15. Avataaar/Circle Created with python_avatars 3Dilettante says:

    is there a fix for that belt squeak on the power steering pump? I got stuck in a sandstorm with my '01 taco and its made that same noise (when i crank the weel) ever since.

  16. Avataaar/Circle Created with python_avatars Patrick Sewell says:

    Had a fun experience similar to this with my 04 grand caravan 3.8 when a shop replaced my upstream and downstream 02s and then a P0430 came out 0f nowhere, but looking at live data, the sensor data was not coming through at all and the shop then wanted me to buy a brand new ECU and reflash it. I did my own research and found out the craziest thing. The auto parts stores sell a Bosch brand "compatible" interchangeable O2 sensor which happens to plug in using the factory writing harness and screws right in no issue… Shop actually agreed to replace the Bosch O2 sensors with exact replacement Bosch O2 sensors in case the new ones that were previously purchased were faulty from the factory, however the issue persisted. I still did more research and found the craziest thing. Apparently these Bosch sensors only send data to the ECU using a negative ground signal whereas the factory O2 sensors used a positive voltage signal to send and read ground data on the same wire. Replacing with any other brand of O2 sensor immediately fixed the issues with the check engine trouble code and the rough running issues. The shop was in disbelief, lol. The only way I found it was watching a random YouTube video that a shop did with the same 3.8 l that was in a Dodge charger or something like that and it had the exact same issue and replacing that Bosch O2 sensor was the fix… Good lesson here is that even if a shop sells you a compatible part and it plugs in and screws in doesn't mean it is still compatible, lol. I actually had to pull up the spec sheets on that exact model Bosch sensor to determine how the data was sent and then of course researched the data connection on my caravan side and that's how I knew immediately that that would cause an issue. Craziest fix I've ever seen in a long time.

  17. Avataaar/Circle Created with python_avatars Aaron Gurtler says:

    This is why different components should have individually styled plugs/receptacles.

  18. Avataaar/Circle Created with python_avatars Krisemann says:

    Installed an O2 sensor on a Volvo 850 a few years back (the old one gave in at 200k miles), and the car would run lean and die. Could not figure out what was going on. Took it to a shop, who could not figure out what was going on either. Finally the dealer looked into it and found out the O2 sensor was the wrong type and was for the 20 valve 5 cyl engines, not the 10 valve engines. I have not had O2 issues on my current car (Audi A8) yet…

  19. Avataaar/Circle Created with python_avatars Thomas Lockard says:

    Nice catch Ray

  20. Avataaar/Circle Created with python_avatars Blade says:

    I was watching you doing the diagnostic on the car, and I was just getting ready to type in the comments, "I wonder if the connectors are backwards", and 5 seconds later you mentioned that they might be backwards. that was awesome.

  21. Avataaar/Circle Created with python_avatars Shooter Ace says:

    Definitely time for a better Scan tool Ray👍

  22. Avataaar/Circle Created with python_avatars w.k k says:

    my one upstream sensor reading wont go over .400 but its moving up n down, any idea. other fluctuates bw 0.00 to .900

  23. Avataaar/Circle Created with python_avatars vilefly says:

    Only 2 things cause fuel trim to skew in opposite directions: 1) timing chain jumped a tooth/VVT cam gear bad 2) swapped o2 sensors. The swapped o2 sensors have a milder symptom compared to the other, and therefore are tricksey and false, just like nasty hobbitses.

  24. Avataaar/Circle Created with python_avatars adam norwood vlogs says:

    This video reminded me of when I had a transmission shop rebuild my transmission in my 2001 Tahoe and they had the electrical connectors swapped so it wouldn’t shift out of 2 gear and they couldn’t figure it out so I picked up and took it to the Chevy dealership and pluged the connectors in the right places

  25. Avataaar/Circle Created with python_avatars five0pd310 says:

    I was finally able to guess the correct diagnosis before Ray let us in on it! I feel like I've now accomplished everything in my life I've needed to!! 🤣

  26. Avataaar/Circle Created with python_avatars Zundfolge1432 says:

    thats wild and awesome ray lol make an ecm go to war on itself by swapping the wires because of a previous dudes change

  27. Avataaar/Circle Created with python_avatars Keith Standiford says:

    Love it! I was screaming at the screen when you first swapped them: "They're swapped, unplug one!" But I didn't have to wait long!

  28. Avataaar/Circle Created with python_avatars Damien Villano says:

    I did something similar to myself. Replaced an oxygen sensor and reset the codes. Only to have the same code come back shortly after that. I replaced the wrong one lol. Fortunately I hadn't thrown it away so it was an easy fix.

  29. Avataaar/Circle Created with python_avatars rick englund says:

    I was watching the Wolverines and Buckeyes highlights and your video was beside on my YouTube feed. You were more entertaining. I’m glad you have many more videos

  30. Avataaar/Circle Created with python_avatars Hawkertech says:

    glad to see your busy, I wonder how long before you have to hire help.

  31. Avataaar/Circle Created with python_avatars Me Z says:

    Ray, you should really put in an exhaust system for when you leave the cars idling. My job's auto shop has this system where they attach a giant flexible hose to the exhaust pipe and it sucks the exhaust up and out the roof. Gotta look out for the wife unit and little ones!

  32. Avataaar/Circle Created with python_avatars Manny Velez says:

    I had same issues with a Kia v6….

  33. Avataaar/Circle Created with python_avatars Andrew Roman says:

    Aside from guessing which connector goes where, you can jump the supply and return pins of the connectors and set a high voltage fault that should read something like "bank 1 sensor 1 shorted to high source" so you know exactly what sensor goes to which connector

    Also another reason to replace one sensor at a time so you don't mix up the connectors.

  34. Avataaar/Circle Created with python_avatars Mark Rix says:

    You know the o2 power doesnt effect the signal right? Just the heater?

  35. Avataaar/Circle Created with python_avatars ᗒᗕ MIKE HUNT ᗒᗕ says:

    Ar end of video .. typical Sony head unit

  36. Avataaar/Circle Created with python_avatars ᗒᗕ MIKE HUNT ᗒᗕ says:

    Great work at diagnosis of the issue

  37. Avataaar/Circle Created with python_avatars Aamber says:

    hmmm vids are way better now…more info on whats, & whys is a huge plus..resubscribing

  38. Avataaar/Circle Created with python_avatars CombatKarl says:

    Who Da think it. I know I wouldn't have.

  39. Avataaar/Circle Created with python_avatars JoeVK says:

    I once did a tune up on a '92 Grand Prix 3.1 and hooked all the plug wires up wrong. I ripped all the plug wires off all at once like the big dummy I sometimes am, and when putting the new wires on, guessed that the front bank was bank 1, and the rear bank was bank 2. Nope. Exact opposite. The engine would try to start, but would kick backwards and die. Grabbed my handy dandy Haynes manual (no internet back then), looked up the firing order, and immediately did the Homer Simpson "DOH!".

  40. Avataaar/Circle Created with python_avatars Roger D says:

    That is a major design error of Nisson! They should have had the brains to KEY THOSE SENSOR CONNECTORS so they COULD NOT be MIXED UP!

  41. Avataaar/Circle Created with python_avatars Roger D says:

    On that Nisson Pathfinder with the suspected swapped connectors. If you closely examine the schematic diagram, you may find that the wire color code will guide you as to which sensor is connected to what output connector. Examople…. the red, black, white wire on pin 2, matches up with the red, black, white pin 2 of the sensor connector

  42. Avataaar/Circle Created with python_avatars Valve Geek says:

    Excellent! 👍😁

  43. Avataaar/Circle Created with python_avatars Jeffrey Evens says:

    Wondering if the "PT" stands for "patience tester." Way to be patient Ray, great job!

  44. Avataaar/Circle Created with python_avatars cheeseburgerbeefcake says:

    That panasonic stereo sound is a blast from the past! Daaaayum. The only thing your guy will be a bit grumpy about is the previous guy not doing it right and asking for your time to at least in part be paid for by the guy who dun did it wrong; but nice diagnosis! Using cable routes to eliminate the doh is 10/10!

  45. Avataaar/Circle Created with python_avatars Joe Schmohe from Simcoe says: