2000 Maxima w/ P0138 and P0139 codes

[ljerkins]

I have a 2000 Maxima SE with the 'service engine soon' light coming on.The car has 42K miles. I had a tech at Autozone analyze it and the 2 codes that come up are P0138 and P0139. From reading other posts, this seems to indicate the rear O2 sensor. This is the sensor that is behind the catalytic converter, is this correct? Is this something that can be done by someone with average mechanical skills? If someone has done this, I would appreciate any help or guidance. Many thanx.............

[audtatious]

Yeah, it's not that hard. You may want to soak the threads in WD40 before removing. You will have to use a wrench and make sure you unplug it first. Do not touch the tip as oils from your fingers may cause misreadings.

[farhan]

I have exactly the same problem with my 2000 maxima GLE with 67K. It gives code P0138. What did you do to fix it? Is this sensor rear to the catalytic conveter? I would appreciate if you could share your experience. Thanks.

[cullenj76]

Make sure that the grounding strap from the catalytic conv. to the subframe is screwed in place.

It's most likely the ECU. You need to take it to the dealer and have them re-flash/update your ECU. This is a VERY common problem though.

What will happen is the light will come on sparatically. You can reset the ECU by unplugging the negative cable of the battery and standing on the brake pedal for a few minutes then let the car sit for 30-60min. Connect the cable to the battery, start it up and it won't come on for a few days/weeks, but it will most likely come back on. I'd bet money that your o2 sensor is not bad, as they don't go bad on maximas until 100k+ miles(I've had a few).

Read this: http://maxima.theowensfamily.c...a.pdf

take it to the dealer and have them perform the TSB as it is explained and it should fix your problem.

[malibu jimbo]

cullenj76, I have these codes showing. with a Service Engine Soon lite on. Is there a similar service bulletin for a 2002 Infiniti I35 ?

[cullenj76]

Not that I'm aware of. The VQ35 uses a revised emissions system. I'll see if I can find something out for you.