HitMan Posted January 16, 2011 Share Posted January 16, 2011 So here's the deal. Several months ago I received a p0136 code (o2 sensor malfunction, bank1 sensor 2) and did the normal thing and just ignored it for a little while then tried the cheap options to fix it. I took the sensor out and cleaned it, reset the code, and then sure enough within a few days the check engine light would come back on. So just this week I finally broke down and bought a new o2 sensor and replaced it, since state inspection is coming up. I replaced the right side after the cat. I hope I'm not retarded or something and replaced the wrong one? I replaced the knock sensor about a year ago as well and everything else is in working order. The truck has 174k so I figured the sensor would need to get replaced anyway. But sure enough today the same code came back up (p0136) after I already replaced it! Anyone have any ideas why this would happen? No other code comes up either. Link to comment Share on other sites More sharing options...
pathfounder Posted January 16, 2011 Share Posted January 16, 2011 If the connector lengths permit, try swapping left side for right side, and see if the code changes. Link to comment Share on other sites More sharing options...
XSrcing Posted January 16, 2011 Share Posted January 16, 2011 You need to reset the ECU and then complete a full drive cycle for the light to stay off. The sensor could be working fine, but the ECU just knows that last time it performed a system check it wasn't working fine. The joys of OBD2 cars. Link to comment Share on other sites More sharing options...
Precise1 Posted January 16, 2011 Share Posted January 16, 2011 Here is some info that was supplied to me by a dealership mechanic. It may help you too... http://www.nissanpathfinders.net/forum/index.php?showtopic=27522&view=findpost&p=513451 Thanks again Derek!! B Link to comment Share on other sites More sharing options...
pathfounder Posted January 16, 2011 Share Posted January 16, 2011 Bank 1 sensor 2 would be driver side post Cat. So Left side rear. Just look at it this way, the right will fail soon if its original so you did a little preemptive maintenance I can't remember if the left side has the same plug, I think its a flat plug unlike the rights box shape. Maybe if you have the old sensor you can splice it into the left sides pigtail until you can buy the right one? [Edit] Right side, are you talking from looking at the car or sitting in the driver seat? Left side versus Right side is based on cylinder numbering. VG33 = #1 on right. Therefore, Bank 1 sensor 2 is the rear on the right side / USA passenger side of the vehicle. The rear sensors only affect fuel trim by 1-2%, but that would be a failure code during an E-test. Link to comment Share on other sites More sharing options...
HitMan Posted January 16, 2011 Author Share Posted January 16, 2011 You need to reset the ECU and then complete a full drive cycle for the light to stay off. The sensor could be working fine, but the ECU just knows that last time it performed a system check it wasn't working fine. The joys of OBD2 cars. I have an OBD2 scanner and I did erase the code. I probably drove about 50miles and then it came back on. Also I could have sworn that bank one sensor 2 is the passenger side... I did a lot of searching before I went ahead and changed it and the general consensus is that it is the passenger side post cat. But now that the code came back up I think its the driver's side. I went by this diagram: The left and the right sensors are both the same on my truck, but the driver side is just longer than the passenger's. Fishing those wires through the engine bay is a freakin pain in the butt too. I even have access to a lift which I thought would make it easier to change but I ended up having to pick the truck up and down several times to fish the wire correctly. Link to comment Share on other sites More sharing options...
pathfounder Posted January 16, 2011 Share Posted January 16, 2011 I have an OBD2 scanner and I did erase the code. I reset the KS code on my ECU many times with my code reader, and it would always come back. I did the resistor fix for a few months, and it worked, but one day I did a full ECU reset (24 hrs with no power to it), and I got bad engine knock, which would not go away until I replaced the KS for real. What I am getting at is sometimes clearing a code and a full reset can have different results. If you have the time, leave the negative cable on the battery disconnected for a day, or at least overnight. Link to comment Share on other sites More sharing options...
HitMan Posted January 16, 2011 Author Share Posted January 16, 2011 (edited) I can do that tonight and I will see what happens tomorrow. Thanks Edited January 16, 2011 by HitMan Link to comment Share on other sites More sharing options...
WOT Posted January 16, 2011 Share Posted January 16, 2011 You dont HAVE to leave the battery disconnected for 24 hours for it to reset. A nissan tech told 2 ways to do it. First way is you disconnect the positive and ground from your battery and then tie them together with a piece of mechanics wire to keep them in contact, leave disconnected from battery and touching for 15 min and it will be fully reset. You must be sure to have the cables disconnected from the battery before grounding the positive wire though obviously Second way was to simply remove positive and negative cables and apply the brakes 5 times to deplete all the energy left in the system, wait for 15 min, and it would be reset. I personally do it the first way now and it works great, all stored codes are gone and reset after 15 min of being tied together and disconnected from the battery, but an IDLE air volume relearn procedure has to be done on my car everytime I reconect, probably because I have a custom cold air intake so the air values are off from the factory settings. Link to comment Share on other sites More sharing options...
pathfounder Posted January 17, 2011 Share Posted January 17, 2011 Learn something new every day. Link to comment Share on other sites More sharing options...
HitMan Posted January 17, 2011 Author Share Posted January 17, 2011 good to know for the future Link to comment Share on other sites More sharing options...
WOT Posted January 17, 2011 Share Posted January 17, 2011 I cant really tell what conclusion you came to either with the 02 sensor side maybe Im just stupid at reading. But if your code is for bank 1 sensor 2, it is for the passenger side Link to comment Share on other sites More sharing options...
HitMan Posted January 17, 2011 Author Share Posted January 17, 2011 I'm gonna reset the system and see if the code comes up tomorrow while I'm running around. I'll update as to what happens... Link to comment Share on other sites More sharing options...
HitMan Posted January 18, 2011 Author Share Posted January 18, 2011 So I reset the system and today coming home from work the check engine light came back on...The same code (p0136). Any other ideas of what to do? Link to comment Share on other sites More sharing options...
WOT Posted January 18, 2011 Share Posted January 18, 2011 Have you done anything to the passenger side sensor or only the drivers side so far Link to comment Share on other sites More sharing options...
HitMan Posted January 18, 2011 Author Share Posted January 18, 2011 Have you done anything to the passenger side sensor or only the drivers side so far I only replaced the Passenger side's. I'm thinking that I just need to go ahead and replace the drivers side, even though the ECU is only registering a sensor malfunction on the passenger side. It's got me stumpped! Link to comment Share on other sites More sharing options...
pathfounder Posted January 18, 2011 Share Posted January 18, 2011 (edited) I wouldn't do that. The code means "circuit malfunction", so check for damage to the wiring from the connector to the ECU itself. It would suck to replace another sensor only to find that some solder and electrical tape is all that you need to do. After that, I would suspect that the front sensor on that side is bad, or the new rear sensor is bad, or the cat is shot, despite being new. Bank 1 is the passenger side. Edited January 18, 2011 by pathfounder Link to comment Share on other sites More sharing options...
HitMan Posted March 15, 2012 Author Share Posted March 15, 2012 well this is a late response to this thread, but the problem still seems to persist. This problem only seems to occur in extreme cold situations, like 20's or less outside and after the car has been running for some time. It's never immediate. Since this post I have had the MAF replaced as well due to other issues, which seemed to eliminate the problem until recently again. Sure enough I have had the code pop back up on me. One thing I have noticed was I was low on coolant, so the truck couldn't fully heat up to that mid position, it would always stay just below on the indicator needle. The o2 sensor was replaced and the wires are all connected properly and not frayed. I am thinking now that it truely is the cat which I don't want to replace. Any other thoughts on this? Link to comment Share on other sites More sharing options...
Towncivilian Posted March 15, 2012 Share Posted March 15, 2012 I haven't found any TSBs relating to oxygen sensors for your 1996 Pathfinder. What brand oxygen sensor did you use? Link to comment Share on other sites More sharing options...
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