I have a 93 civic cx and just put a 4-2-1 header on it and now my check enging light comes on after about 5 to 10 min.
I still have the stock oxygen sensor and catalytic converter on as well. There is also a cat back system already installed prior to the header. Any ideas on how to fix this problem??

 

its most likely something with the O2 sensor... give it a wiggle or unhook it and try hooking it up again.

 

So you figure its jsut a bad connection? I will give it a try thanx. I have had ppl tell me having the cat on will mess my oxygen sensor readings up, ever heard of that? I also have a cool air intake but that went on after, dunno if that would make a difference?

 

Disconnect the battery for a minute, then see if it still happens.

 

might be time to repace them anyway

not having the cat on might trip the light, but having one wont

 

you could also do what NTX said... but when they are disconnected touch the leads together (away from the battery of course) then reconnect to the battery and let the car idle for about 10-15 minutes. It will reset the computer in your car and force it to relearn everything it knows.

 

Hey I reset the comp and now it ran good for the 15 min idle time then I took a little ride and still fine. But when I was on my way out to my gf's it came on again?[sm=smiley5.gif]

 

sorry man... Im outta ideas now?

 

Have a local shop possibly check for error codes. Some places check it for free....i think.......

 

Ok thanx for the help anyways it was worth a try.