slag

Bought this car and it had the CEL on. Read codes which indicated bad knock sensor and evap purge valve were shot.

Examined knock sensor and it was all cracked up. Replaced with good used one.

Did same with evap purge valve--it was all corroded inside and broken up so I replaced it with a known good one.

Reset CEL by using the procdure in the how-to by turning screw right, wait 2 seconds, turn left, wait 2 seconds, repeat, etc.

Now, my CEL stays off for about 90 miles or so and then it comes back on. If I read the codes, the same 2 issues are there. I figured it was a ghost in the system so I reset the computer, unhooked the battery for 12 hours, reattached, drove it in to work, and blam, same thing. The cel stays off all the way into work and then after I come home that evening, it comes on during the drive home.

Ideas? It makes no sense to me at all. Is there a common ground these 2 sensors share that could be bad?

mzmtg

iTrader: (11)

You shouldn't have put in used parts.

Get new replacement parts.

slag

I'm 100% sure the parts are good. When I would reset my CEL with the old parts, it would come back on in a matter of minutes.

New replacement parts for these 2 issues would cost too much.

robert1947

slag -- Sorry I don't have any advice. Could you tell me what code you were getting that indicated a bad EVAP purge valve? Was it 0903 or 1008? I notice on the write up under code 1008 that it suggests also checking fuse #58 (10 amps), but I don't know where it's located.