u71n44

Can it hurt a 2k0 maxima if this sensor is not replace imeediately, and exactly what does it do. Any responses are greatly appreciated.

Zero Deuce SE

It depends on which one is bad. If it's one of the rear ones, it will most likely affect your gas mileage. Do you have a check engine light or code for an O2 sensor?

sloppymax

iTrader: (8)

rear (secondary) o2 should not affect gas mileage as its only function is to monitor the precats (cali spec) or precat and main cat (fed spec). if you have a bad primary o2 sensor then it will affect gas mileage as it is one of two configuring tools for your a/f ratio. you have a primary on each bank and one secondary if you fed and two primary and two secondaries if you are cali spec.

u71n44

per my receipt from pepboys diagnostic says..
"PO138 o2 sig bank#1 sensor#2.

Does that help?..

u71n44

and is this an item covered by the Federal Emmission Act.. that requires the dealer to replace.?

Ben

Sensors are not covered on the Federal Emissions act.
I have head (but don't know for sure,) that the intake O2 sensors failing can cause engine damage because of to lean a mix. I don't know the details though.

nismo_star

iTrader: (8)

P0138, P0139 are part of a bulletin from NISSAN which its replacing both rear o2s and reprogramming of ECM.
Unless you had them done already, then your o2 harness may have a cut in it.

8yrs /80K mi

u71n44

are you saying they are covered by the 8yr/80k federal warranty.. as far as you know....

Zero Deuce SE

It affected my gas mileage as soon as my check engine light came on. My mileage dropped way down. After having both rear O2 sensors replaced and reprogramming of my ECM, it was back to normal.

u71n44

but which was your problem.. the one in front of cat conv or the one in the rear.

Zero Deuce SE

The service bulletin (NTB02-051a) only refers to rear O2 sensors. I had codes P0139 and P1147. http://maxima.theowensfamily.com/tsb...=2000&tsb=none

zourtney

i have this issue at the moment, too. The nearest dealer is 70+ miles (of snowy roads) away. I recently had my MAF fail, and have been having a very high, 'bouncing' idle. I replaced it today, but it still have the same issue.

Could my rear o2 sensors be to blame for this bad idle? The only other thing I can think of is that my ECU needs to re-learn the fuel/air ratios.

(Sorry for butting in...)

Zero Deuce SE

Is your CEL on? The TSB mentions a special reprogramming procedure for vehicles with an updated MAF. If you have any bad O2 sensors right now, you will have to get them replaced along with the reprogramming to make your car run right again.

zourtney

from what I understand, the original ECU programming will trip P0138/9 SES codes when in fact the sensors are fine. I've heard that reprogramming will keep this from recurring, if your sensors are in fact ok. I plan to get this done some time, but the nearest place that could do it is 70+ miles of snowy, icy roads away As for the MAF reprogram, I believe it's part of that same firmware update.

dkotanto

iTrader: (1)

Is the CEL the only indication that your O2 sensors are going bad? I mean, can you have a bad sensor and the CEL will not turn lit?

u71n44

Good news...
I called my extended warranty company and the o2 sensor is indeed covered by them. I'm glad I did purchase this gold plan. I"m also getting my powerseat fix on driver seat that will not move forward or back. So, the extra money in the extended warranty is definity paying off now. I got 2yr9months left or 32,000mi more on it. wwwwooooohooooo.