Help needed! Engine running rough after header install.
Help needed! Engine running rough after header install. I have a 98 C5 vette. I just installed headers on it. After the install I started up the engine and now it seems to be missfiring. It doesn't run too bad at idle but when you put a load on the engine it shakes and backfires. I left the cats and O2 sensors on it. It is throwing a code for low voltage in once of the O2 sensors. But I took it to a corvette specialties place here in Tulsa and they said that the sensor wasn't the problem but after hours and hours of diagnostic testing they told me to just take it to the dealer. I have searched ls1 forum and corvette forum for the answer to my problem but I haven't found anyone who has ever had this problem before and no one on corvette forum will help. If anyone has any information or any ideas on this problem please let me know. Thank you.
Yeh Yeh, that's messed up ain't it. I figured they could have at least told me if it was misfiring or something. Shouldn't they be able to? All they could find was a vacuum leak.
I made sure the O2'S were in the correct places yesterday. That was my first thought. But they are in their right places. I checked the wires to make sure they wern't pinched, broke, or loose. It all seems right. I'm going to unplug the coil pacs and spark plug wires like he said and see what happens. I've reset the computer and made sure the connections are right, but I'll go over them again. It seems like it's running too rich also. You can't smell the gas but it has made a big boom/ backfired a couple of times when I have started the car.
Haven't pulled them out yet. I'll check them when l pull off the wires and coil pacs. When I was putting the spark plug wires back on after the header install, I didn't see any cracks or remember getting close enough to hit one. I'll check though. Thanks.
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Verdad Gallardo Ok, all the spark plugs are good. I checked the spark plug wires and coil packs. They are working correctly. The only codes I have are a air system code because of the headers not having air runners in them and a engine speed output circuit code, which I believe is because of my tach not working. It isn't even throwing the O2 sensor code anymore. Where do I go from here? Any ideas?
Finally solved! After the header install, we replaced the spark plugs. Turns out that on the first set of plugs, the #7 plug had a crack soo small we had to get a magnifying glass to see it. We then replaced the plugs with new ones, but there was no change in the way it was running/missfiring. Apparently the computer learned how to run with the missfire and when we changed the plugs it didnt change. A guy in Oklahoma City had to change/tune the computer to get to run like normal. He never had heard of a computer not changing back or relearning itself.
Thank you to everyone for your help. It was greatly appreciated.
Thank you to everyone for your help. It was greatly appreciated.
