So a month or two ago my MAF died. Not wanting to spend $500, I bought a 2K1 MAF, moved the thermister from my MAF to this one, installed it, and did the timed-pedal-pushing ECU reset procedure. All was good until a few days ago, when my SES light came on. Took it to autozone and got P0139 and P1147 out of it. Before I replaced the MAF, I would pop P0139 every so often when I'd take the car on a long trip. This is the first time I've gotten P1147.

http://forums.maxima.org/showthread.php?t=469143

I found this thread, which states there's a TSB for this, and I should replace those O2 sensors and get a reprogramming. What I'm wondering is if this is actually due to my franken-MAF and not my O2 sensors. It seems weird to me that they would both fail so soon after replacing the MAF, but what do I know.

Basically just asking for advice before I go buy a couple O2 sensors and give the dealer some money. The MAF still seems to be fine...I didn't get much power gain from replacing the MAF aside from a bit better low end, but my gas mileage is pretty good. 22-23 in city and 29-30 on the highway.

 

I think you just got lucky


I've had the '01 MAF in since January with no O2 problems.

 

i just did the same thing over the weekend, my car didnt throw codes for about 3 hours, but then the light came on, not sure whats its on for yet, but im sure its just my O2 sensor which was throwin codes before

 

Bumping this because I just got these two error codes again. The SES light for this always seems to come on in Colorado when I've been driving on the highway for several hours at high altitude (5-6000 feet).

I'm going to the dealer tomorrow to have a couple recalls done, so any tips for what to do about this? It seems like the O2 sensors might not actually be bad if I got these same codes almost three years ago and did nothing about it.

Edit: Related question: The TSB mentions doing a different ECU re-program depending on whether you have the original MAF or the AM600 updated MAF. Since I have the 2K1 MAF, which one should the dealership do?

 

I think sometime the o2 sensor got dirty therefore throwing the code. There is my story... I got the same two SES code as you for the past few weeks. Before I replace the o2 sensor, I spray some WD-40 to loosen it. But when I move the car to the garage, the light went away! So I don't know what happen but as of today the light hasn't come back.

 

I was getting the P0139/P1147 codes too, put in a new O2. Codes came back at about 190 miles, reset the ECU and they've never come on again and it's been about 15 months. Others have to replace both rear O2 sensors and get a reflash to correct the problem. Could be mine was already reflashed at some point before I bought the car and I just had a bad O2.

 

Well I ended up getting the reflash at the dealer (update for MAF and ECU I think) but I didn't replace the O2 sensors. The light's off, we'll see if it comes back on or not. They said I needed to replace O2 sensors and I asked how they knew that, and they said because of the codes from the computer and the fact that they looked rusty. Whatever, I'm not convinced.

 

Just to update, I got 30 mpg average for almost 1000 miles of highway driving at low altitude and the SES light hasn't come back on. Better highway mileage than I've seen in a long time, I think the reflash did me good.