p1281
 

So I started throwing this code about a month ago. I have used cipher to clear the code twice already, hoping it was a fluke, but it comes back after ~300 miles. I think the code is an Infiniti specific code for A/F sensor driver's bank (I think the one that is in the cat).

I have S/C with vpro ems/osiris reflash and the sensor is plugged into PE metallic HFC's. I have o2 foulers stacked to avoid the cel, which has worked the past few years, and I recently passed emissions before I threw the p1281 code.

I'm not sure if the code is related to the fouler possibly going bad, or the sensor, or harness? Anyone have any thoughts/suggestions before I go to the dealer to check the harness/sensor/etc.?

thx.

ok, so I think this is the AF sensor located in the manifolds, or headers, pre cat. I think the one that is bad on my car is the driver's side. I will likely replace it tomorrow.

replaced the sensor in the manifolds. but now im throwing the code again and my idle is off :(

nyone have suggestions?

Also have the same problem, I have HFC's if that makes a difference. I searched and found threads saying what the code is, but none that really go into how they were fixed.

hmm, I thought the code was for the sensor in the manifolds/headers. The sensor in the cats is the heated 02 sensor. Not sure how HFC's would pull a p1281, but if someone knows, plesae chime in.

From what I've been reading the FSM, the sensor sends a voltage signal to the ECm regarding A/F mixture. When p1281 is thrown, it basically means the ecm is not getting a signal from the sensor. This could either be becuase the sensor is bad (dirty or burnt out), the harness or fuse for the sensor is open or bad, or the A/F mixture diviates too much % wise from stock values. Since I am FI, I know my A/F is richer than stock values. But I'm confused at to why I am now only throwing the codes, whereas awhile back after SC install I wasn't thowing p1281. Not sure if it is hardware failure or tune related. Then, there is the issue with my idle as well. I would hope that with Upreve flash, Vpro and pro tuner, this can eventually be fixed...

Anyone with more info, please chime in. thx!

Well the front AF's and the rear O2's communicate with each other. That's how you get codes for one or the other. Technically, I'm throwing an AF sensor heater code. But I replaced BOTH AF sensors just because mine were OE and I have 118K on the clock. The light stayed out for about a week and then returned, with the same code, I'm tempted to throw stock cats back on, or even an O2 sensor for the driver's bank.

Bump, Come on guys help us out here

i had a 1283, they said that was a lean-running bank... maybe 1283 means rich? im not sure..

It may mean the other bank, but we have 1281's. I checked with a Nissan and Aftermarket scantool. The Nissan one just says A/F Sensor, the aftermarket one says A/F sensor heater...

So far, I am still throwing the code and it the cel is coming on sooner, after resetting. One thing I noticed is that after the cel came on, my idle really started to go nutz and will not settle--jumping from ~200 rpms to ~1200 rpms. Next week I plan to have the sensors and harness/fuses checked, as well as change out my spark plugs (1 step colder NGK iridium), which I think might have been fouled after running pig rich from when my vpro got messed up. Also a pressure test to check for vacuum leaks..Maybe P1281 and my idle issue is related?

What year is yours? I know that the 03's have a TSB where you need to turn the ECM's self learn after replacing the a/f sensor. Not 04 though.

05 revup

Bump for help

There's a lot to check for, so I think it may be hard to diagnose over the Internet. Currently doing a pressure test for vacuum leaks. If there is a leak, tuner/tech thinks it may be my cosworth plenum.with freezing temps--metal contracting but carbon fibre end caps do not. Also checking plugs. From a tune perspective, it seems that one of the banks is running more rich/lean than the other, which may be the culprit for the idle and engine running rough during idle surge.

My code is for the heaters. I'm just stuck. And I don't feel that paying the dealer to daig is the right answer because they'll probably just blame my high flow cats because I know how they are. F*ck. This is frustrating.

How often do you go through plugs? My boosted NX is lucky to get 2000 per set! But getting that thing to idle right is impossible due to the P/P head and cams