I'm getting a random multiple cylinder misfire code (and random cylinder misfires on acceleration odly enough, worsening over the summer). My headers are coated on the inside and I've recently been road racing (prolonged hot temps). The O2 were new with the new headers (~4000miles ago). Just wondering if this is a known problem and if I should start there, thanks-

 

I'd say that the Jet-Hot coating will not. Its supposed to be the best out there, and I put new o2's when I did my coated's with no problems....

 

i had my jethots installed and about 3 weeks later my o2s went out...they wernt new but both of them went out after about 1-1/2 months

 

From what I have read, the oils and coatings that are on a new header or any exhaust component will cause the O2s to go bad. You may want to search but there was a big conversation about this a while back. I doubt the jet hot coating would do anything. When I installed my coated Pacesetter LTs I ran my old O2s for a couple of weeks, and then installed my new O2s after that. No problems so far.

Aaron

 

Thanks for the replies. My coating is from AS&M. I was wondering (97 formula) if you can tell me what yours was doing when they "went out". I just wonder if this is what is happening since I have been racing so much this summer, the headers have been hotter...Looks like I know what I'll be doing tomorrow-

 

Found the old threads, thanks for the advice-

 

well my car would have a slitly rougher idel when it would go into open loop.
also i have auto tap and looked at my o2 reading could see that the long term corrections for for my right side was like 15%. at first i thought it was from a bad spark but a week later i would start getting the SES light saying some crap about the o2s. i would say get a friend to scan ur car or waitfor the ses light to come on because o2s arent cheap (at least to me)

 

One more thing (sorry)-
Am I right that when the car is cold it is in open loop and therefore the O2 sensors have no input and therefore if I take the car out when its dead cold and hammer it and it runs fine then worse when it warms up that this is more evidence that it may be the O2 sensors? Or would this go against it being the O2 sensors, or does it matter at all? Just want a little more evidence before I go drop a load the the parts store - thanks (I dont know anyone with a scanner)

 

Hard to say there. At WOT, the computer pretty much ignores the O2s and uses a WOT fuel/spark table that's preprogrammed into it. Have you checked your wires since you did the headers? Some of them may be burnt.