The service engine soon light can on yesterday on my 2001. I pulled the code with my carchip and it came up as p0140 o2 sensor circiut no activity detected bank 1 sensor 2 . Does anyone know which sensor this is? As far as I know my car has four o2 sensors, so trial and error is not an option.

 

what kind of mods do you have on your Car, and what brands.... I have a stillen Y pipe and it threw the same code P0140, It means its reading High Voltage to the o2 sensor... Do you happen to have a Y pipe Tooo???

 

bank 1 - rear manifold
sensor 2 - the one after the pre-cat

It will be the one with the WHITE harness. The sensor third one from the left right in front of your engine behind the radiator, under the spark plugs and coils

 

I have the same problem, p0138 and p0139. Is this something I can fix myself or do I need to have the dealer make the repair?

 

o2 sensor replacements are easy with the o2 sensor tool. i have had problems without it. one reason you may want to see the dealer even if you replace the part is because nissan recommends a flash update. i received p0140 a while back and nissan replaced both secondary o2 sensors along with the flash covered under warranty. if you want to know if the flash is necessary, i could not tell you that. i have had no issues with the secondaries after that but on the other hand, i never had the flash for the new maf and have had no issues afterwards either.
here is a link to studman's site which contains the tsb itself.

 

www.nissan-techinfo.com

look up tsbs for your year and see if it applies towards you.

 

The TSB definitely applies to me, 2000 GLE. Anyone know if the repair is covered by a warranty?

 

2000 maxima, i doubt it. You should look into the details on that. Emissions warranty is a little longer but you could over the mileage also

 

do you have any sort of extended warranty?