I have a 4 cylinder 99 accord lx auto that has run flawlessly and has been well maintained. It's on 115K miles (mostly highway) and I just got my first dreaded check engine light. The drivability of the car is the same, and I haven't noticed any difference in the performance or gas milage (so far). I went over to Autozone and used their OBD2 scanner which read the single code, P1149. After some googling I found out that it basically means the primary O2 sensor isn't working properly. Then I found this Honda Service Bulletin on the web:

http://www.driveaccord.net/forums/at...hp?postid=5903

The bulletin says that it's a fault with the ECM/PCM (computer?) erroneously reporting a bad O2 sensor and that the ECM/PCM needs to be replaced to resolve the problem. I think the computer is a $700 part, much more expensive than an O2 sensor. Nonetheless, I wouldn't want to replace the O2 sensor if it is not going to fix the problem.

How do you guys recommend I try to figure out if it's really a bad sensor that needs replacing or if it's just the computer? If it is the sensor should I notice the gas mileage getting much worse? Or can that also happen if the computer *thinks* the sensor is bad and changes the fuel ratio. I don't want to end up having to change the ECU just to get rid of the check engine light, but I don't want to end up with lousy gas mileage either.

Any suggestions are greatly appreciated. Thanks!

 

Take it to the Honda dealership.
Chances are they will do a goodwill repair

 

I would think that after 115K miles, that the O2 sensor might actually be going out.

You will probably hear the same thing at the stealership.

 

Well, I have same problem too. I think it faulty code, I'll keep driving till it die. Do this 1st..unplug NEG batt cable for 30 second. Then drive around and see if CEL comes on. Like I said, I have the same problem over a year already, everytime it come on, I reset it, I have the ODB2 code reader, so it take me few second to do the job. No need to run on to AZ all da time Good luck.

 

reset the computer with the scanner or disconnect the battery if the same code comes up then worry about it . and don't forget theres the cost of reprograming your immobilizer keys !

 

I've been noticing a lot of 6th gens have been having cels go off lately. try this, I haven't had an issue since I installed it.