i own a civic 00 ex and my problem is when i come to a stop my car idle drops till it dies. its worst if i come to a sudden/fast stop. i do have a bad o2 sensor, oculd that be the problem?
Well first off, fix the problem causing the O2 sensor code. This critical sensor optimizes the air/fuel ratio to give the engine the best performance and gas mileage. You also risk rapidly destroying the cat if the O2 sensor isn't working.
Regarding the idle problem, try retrieving possible CEL trouble codes from the ECU (see link in my signature) and also try cleaning the IACV on the throttle body (see forum DIY).
make sure you find out which o2 sensor is the problem, chances are, it's the primary that usually fails, and then go from there, no need to clean the IACV and take a chance that he might mess something up in the process. (that is if he's not mechanically inclined)
well if you got a bad o2 sensor might as well replace it that will prabably help. my buddies 88 accord did that. he would brake it would die. his had a carburettor tho but he found out that he had a vacuum problem he fixed that and it went quit dying