Well I went to Autozone today and had them read the code that was being thrown. It was the o2 sensor on bank two. I have a leak in my y-pipe flex section, could this be causing the code to be thrown. I reset the SES light and it hasn't come back on yet, but we will see.

 

I beleive that's the o2 behind the cat. There is supposed to be a certain diffential between it and the o2 sensor on bank 1 in order to measure the catalyst efficiency. So if you leak exhaust before the cat it could throw a code the way I inderstand it, since it would fubar the differential measurement.

 

are you fed or cali emissions? O2 sensor behind the cat doesn't do anything... only if your main O2 sensors go out, then the rear sensors are used as a backup for A/F control. My rear O2 sensor on bank 1 has been bad for a week or two and I get the code... car runs fine tho and the other sensors are fine.

 

Man You read my post a few threads down, I'm having the same exact problem, but not sure which one it is. I think the Heat is just killing the O2 sensors..

Where you from? I understand your Sig

 

mine is cali spec so I have 4 sensors... 2 main ones, and 2 behind the precats... the one behind the front precat is bad. I plotted the voltage it put out and it was above 1V for a while... so it is bad. Since it doesn't do anything, I'm not going to worry about it right now...

BTW, I am from pakistan...

 

If I'm not mistaken, o2's are covered under emissions warranty, right?

 

Quick update. Went to Autozone Got Error Code 0138 and 0139 Bank 1 #2 sensor. I think thats the one before the main cat not 100% sure.. Any of you guys know? my car is Fed Spec.

 

your O2 sensor behind the main cat is bad...

P0138 = insufficient voltage reached from rear O2 sensor
P0139 = response monitoring slow from rear O2 sensor

For fed spec, you have 3 sensors... two up front for each bank and then one after the main cat. These codes are for the one after the main cat.

 

Thanks again man, Thats exactly the information I was looking for. Do you have a service manual or what? WHere do you get this information from.

Also Anyone know what OBD II reader Nissan Uses. I won't mind having one of those gizmos ... Was looking online and some of those OBD II readers are like $130. thats not bad. Anyone Recommend a brand or Model of OBD II?

 

I've got the ESM... comes in quite handy

I have this OBD scanner... it hooks up to a laptop through a serial port:

http://www.obd-2.com/

it has some neat features... you can plot and store all kinds of data with it.

 

It will come on again for sure. Let us know how many miles till it does. I bet 90-110miles before it comes back on.

 

Mine came on shortly after 20 miles of driving, and I resetted like 4 times already. Gotta fix it from Nissan dealers

 

If you know Which one it is, why Pay Nissan to Fix it. Fix it yourself.. It takes about 5minutes to replace an O2 sensor.

 

Nope, gotta get ECM reprogrammed-------------check the TSB, it has all the info.

 

Which ECM program are you talking about? The latest update?

 

m o2 sensor recently went out and i want to replace it but since i have a WSP y-pipe will it just make it go out again. And also do i have to get the computer reprogammed. If so that means that my local body shop cant fix it. that seems a bit ridiculous. But it is nissan

 

I have the Cattman Y Pipe for 3 years and My Rear O2 Sensor just went out about a week ago. As for resetting, Just unplug the battery for 5minutes and it'll reset itself once you have replaced the O2. How much are they anyway, I havn't checked price yet.