I have a '99 Accord LX AT 4cy with 84K with no mods other that removing my black silencer box for the air intake, don't think that would cause the problem. Check engine light came on while I was driving. Hooked an ODB2 scanner on and there it was P1149 (Air/fuel ratio sensor range/performance problem). Can anyone tell me what may be wrong? May just be a bad primary O2 sensor but I'm not sure. I Did a little research online an found out that on Honda's Bulletin # 01-031 states that if code P1149 is found on a 1998 thru 2000 Accord, the vehicle's ECM/PCM (computer) must be replaced. Seems like the original computer's program is too fussy about the performance of the air/fuel sensor. I'm not sure if this is true or not but if anyone out there has encountered this problem and can help me verify my problem it would be great. This really sucks since I had just got my trannsmission replaced by Honda about 3 months ago, and no it wasn't under warrany !!!!!!!!

 

Air/fuel ratio problems would be indicative of the O2 sensor, which is a common thing to go on Hondas.

How did you blow your tranny so soon?

 

I guess I'm a lil heavy footed, but I never tried to shift an AT tranny like I know some people do. Plus I found out that the shop I brought it to for my 30K & 60K tune-ups used cheap crap for tranny fluid.. dumb asses.. thought I could trust them since they were friends of the family Never will they touch the car again. The new trannys doing fine now at least.

 

How soon after removing the resonator did you get the code?

You may want to reset the code, pull the battery terminal for a few minutes and reconnect and let the car idle and reset the ratio before spending money on a new O2 sensor.

 

It's been about 2 yrs now

 

Did you reset your ECU after removing the box? Maybe the ECU needs to account for the extra air it's getting.

 

I had the same code two years ago. Honda has a TSB on this. And the fix is to replace the O2 sensor and replace the computer with updated parts.

 

I resetted my ECU about 5 days ago and the light didn't come back on again. My PCV valve was replaced since it was kind of clogged up. I also changed my air filter, cleaned my intake manifold, and poured a bottle of Chevron Tekron fuel system treatment before I resetted my ECU 5 days ago. I'm hoping that took care of the problem. Please continue to give me feedback if you had the same check engine codes pop up.