Car is back firing after header install
 

After i installed headers on my 02 trans am around 3k it sounds like its back firing and when i get on it the check engine light flashes for about 30 seconds and then turns off. Now the check engine light is on and throwing an passanger 02 sensor code. when we intalled the headers we replaced the spark plugs could this be bad gapping or maybe a wire not on all the way... thanks guys

Yeah, mine too but I don't have SES light. It does a once in a while misfire also.

A flashing check engine light means there is a misfire. Check all your plugs and wires.

The code for the o2 sensor. What is the exact code? Is it bank 2 sensor 1 or bank 2 sensor 2?

It is the front passanger 02 sensor the back 02 sensors have sims in them

The front o2 wires didn't touch the headers and burn through did they? I've seen that before.

no they did not

What's the exact code number? It might just be time for a new oxygen sensor.

but would an 02 sensor make it back fire?

Mine was backfiring after header install also. Definitely check the plug wires. I have MSD wires and they are very difficult to snap on and even then it is not a very assuring "snap on". I say pull each plug wire and reinstall them paying very close attention that they are being fully connected. I could have sworn mine were, and they were not. On my wires, I learned that even though I was pushing as hard as I could and were as far as they could go, a couple still were not connected properly. I also had this problem with the coil pack connections too.

Did you install the plugs before or after the headers were in? If you installed them before the headers, you may have hit a plug and cracked the porcelain also. I installed my plugs after the headers were in to avoid this.

I'm gonna recheck my wires to make sure its all secure.

thanks a lot man i am going to check this tomorrow

Double check .. no , triple check your spark plug gaps and wires. Same problem with mine, but it was constant hesitation and backfiring.

A thing to look at before you replace your O2 sensors, check and see if your extensions were melted by your header primary. I was throwing a bank 2 sensor 1 code and multiple cylinder misfire. Found out that the wire on the O2 extension melted due to contact with the header primary causing the O2 problem. I fixed that and the car still hesitated and backfired. Took the plugs out , checked the gap , cleaned them and reinstalled . Car still hesitated. :bang: So being really pissed off at this time , i take it to a shop that had a diagnostic machine and i found the #7 cylinder was misfiring. Mechanic took out the plug, checked the gap and sure enough , it wasnt right. That's the same plug that barely tapped the header primary when i was reinstalling it, closing the gap .

So it goes to show something that small can cause major engine problems . Hope everything gets worked out !

i would double check the plugs and make sure u gapped them right and make sure ur wires on are there tight.

but it will run rich after the header install.

Once again thanks all

my car backfires when the cut out is open. Not a big gun shot back fire but sometimes when wot and I let off it sounds to spit back pretty good. It does hesitate on the bottom sometimes. It doesnt do it all the time but most of the time. When I put my bosch platinum 2's in about 3 months ago I dropped one plug and it bent one side down so I bent it back up to the same gap as the other. Could this be a problem? I have checked all my plug wires multiple times?

I didn't read the whole thread but I'd try swapping sides with the o2 sensors. Afterwards, if the code moves to the other bank, you've found your problem.

Try some NGK TR-55's instead of the Bosch, that may be your problem. For some reason, I had one Bosch platinum plug in my car when I did the plugs, the rest were factory AC's. The platinum was completely gone off the Bosch plug, I dont know how it fired at all. Buy the regular TR-55's, they are cheap and it shouldnt be so bad to switch them out since you have done it once already.

i had this problem about 2 years ago with my TA.. you didnt mess with the coil packs did you? I took the coil packs off my '98 just to make the swap run a little smoother.. (i know that the coil packs on the 01-02s are all connected, but make sure theyre all on properly) i checked my plugs and wires first, next fuel filter/lines, then finally the coil packs... just giving you an idea..

Ok im goin to change them anyways I heard to many bad things about them. There good if you want them on your mini van or your 4 or 6 cylinder but there not rated to good for the ls1 from what I heard...What should I gap the ngk's at?