Comptech Header check engine light! Help!

[RyRy210]

Okay, I did a search but did not find anything close to what I'm experiencing. I'm pretty positive it has something to do with my new headers since this problem started right after I installed them. I replaced the rear 02 sensor with a new one in the process. Well, here is my problem:

I installed my comptech header. I drove my car normally after the install. No full throttle accelerations, no abrupt braking and all that stuff. No problem. Then one evening I decide to test out the "power" of my new header, so I drove my car really hard. Next day I start my car, the check engine light came on. Took it to the dealer, and they told me the 02 sensor came loose, so its fixed. Then after many miles of normal driving, I decided to drive like a mad man again. Voila! Check engine light the next day! This time the dealer didn't have an explanation, but for some reason it went away days later. Then its been quite awhile since the light came and I decided to race my car again. Man.... the light just came on. This is pissing me off. I'm debating whether I should install my OEM manifold back on and just deal with the slower car. Has this happened to anyone before? Help!!

Ryan

 

[ScienceofSpeed]

A couple ideas:

1. unplug clock fuse, allow ECU to reset
2. 02 sensor was fouled during installation
3. 02 sensor wires melted on header due to installer allowing the wire to touch hot exhaust parts or engine. They are now shorting.

Cheers,
-- Chris

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[email protected]
http://www.ScienceofSpeed.com

 

[topdaytrader]

How do you unplug clock fuse, allow ECU to reset? Do you have any pics?

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Super Xenon

 

[Lud]

1. Open Hood
2. Open Fusebox
3. Remove Fuse Labeled "Clock"

 

[NoClgDeg]

Did you spray something on the o2 sensor? Otherwise I agree with chris on the wires may have been melted.

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91 Red/Ivory #2061

 

[Larry Bastanza]

Ryan,

I have to agree with Chris. Since this is kind of intermittent, that seems to most logical. When the 02 sensors get messed up during installation (usually due to WD40 or the like being sprayed on them) they "clear" up after a while, once they do, they are typically not intermittent.

Some times they are just shot, so the light is permanent, and you need to replace them.

You can get the codes yourself to see what the ECU is telling you. If I recall it is section 11 in the service manual here in Prime.

HTH,
LarryB

 

[docjohn]

agreed if it aint the sensor bolt its the wires going into it.

 

[SNDSOUL]

I had the same problem. The fix was easy. Evidently the wires going to the O2 sensors were pulled too tight and everytime I got on the car, the engine moved and the end of the rear O2 sensor rubbed on a crossmember just enough to trip the check engine light. I didnt figure it out before I replaced both O2 sensors. Oh well, I made a slight adjustment and all was well.

 

[RyRy210]

Okay, got my car back from the dealer, and they replaced my 02 sensors for free. The check engine light was off, and I was cruising on the freeway going back home. After exiting I took the long route home, going throught a stretch of road with a lot of pot holes and bumps (this route had zero traffic lights). After 3 mins of slow driving my check engine light came back on. I think it came on when I ran over a pot hole. But this I'm not 100% sure. Anyways, hope I can get more help. If this doesn't get solved I might just go back to OEM. Thanks.

Ryan

 

[NSX Tech]

Did they replace the front 02 or the back 02 ?

 

[RyRy210]

They replaced the front 02 sensor during the install and they just replaced the back one this time around. I really don't know what is going on.

 

[Lud]

Check the 02 sensor wires and connectors.

 

[ScienceofSpeed]

Actually ran into this problem at the track last week. My 02 sensor wire shorted on the headers from the heat melting the insulation off the wires.

-- Chris

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[email protected]
http://www.ScienceofSpeed.com

 

[Larry Bastanza]

Ryan,

Did you or the dealer pull the codes? Maybe you're chasing the wrong thing?? I agree to check the wiring again and connectors as Lud suggests, but I do not have a clear understanding of the "code" that is turning the light on.

"Just the Codes", Maim, "Just the Codes"!!

Trying to Help,
LarryB