Headers installed then developed a misfire!
Headers installed then developed a misfire! Alright having a slight issue. I had my headers and Pacesetter Y pipe installed with a TSP rumbler exhaust. I had the PCM tuned for the o2 delete as well as the egr and air. The car ran fine for about a week and then today i picked up a misfire at random times. If im cruising at like 40 and just give it some slight throttle the car misses and then backfires. At random stops it seems to miss on occasion as well but not all the time just randomly. Well as im driving i notice it sounds like I have an exhaust leak. SO i get under the car when i get home and find that the header and ypipe are leaking on the passenger side. So i know i have to get this fixed no big deal really but would this cause the misfire at anytime. The misfire really doesnt happen all the time just randomly real random. I put the car in third and punch it and get no issues with misses. Its odd. The plugs and wires are all brand new as well oil was changed it ran fine at first after the install just now have the leak and a random miss any help guys? Thanks.
TECH Senior Member
Joined: Dec 2001
Posts: 5,398
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From: Jacksonville, FL
You didn't mention any codes. Something free and easy to check is to start the car in complete darkness and rev the engine - then look for any plug wires arcing on the headers. Pay particular attention to #6 - found that after my buddy installed his SLP's.
No codes flashing through the PCM at all. Like i said its random. I checked for arcing wire and even then did a complete inspection of the wires with no problems at all. Iv got great clearance on the plug wires. All the plugs and wires are new as well. Im going to tighten the clamp near the leak and try to stop it and see if it remedies the situation. Any more ideas would be greatly appriciated, and like i said its a random thing. THanks.
Mine ran like crap after LT install, it would bog and "misfire" under load. If I put it in neutral and revved it, it seemed fine. Finally found a loose plug wire, its been fine ever since!
alright checked everything again this morning. No loose plugs or arcing wires. I attempted to tighten the clamp on the header y pipe with no luck still leaks not as bad but still leaking. Im thinking what i heard a miss may not actually be a miss but assosiated to that stupid leak. It apears that the engine is runs great and the hicups when the leak is at its greatest. SO im going to a exhaust shop and have them fix the leak. Any more ideas would be appriciated. Thanks.
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Joined: Nov 2003
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From: Wichita KS / Rancho San Diego
Originally Posted by black00TA
did you change your plugs when you installed your headers? it is a must to do when doing headers.
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Originally Posted by RevGTO
Why? Because of the chance of having cracked one during the install?
plus the swap to TR55's when doing LT's is a match made in heaven.
EDIT: what type of plugs and wires did you use and what did you gap them at?
You have had 1 of 2 things maybe both happen. You have either burned an o2 sensor harness causing it to short out and/or popped the eng sens fuse in the process.
Check that your o2 harnesses are off the headers and check that fuse.
Check that your o2 harnesses are off the headers and check that fuse.
When did you get new front O2s for it? I'm with the fellas on the O2s, plugs and wires. Maybe the leak is throwing something off when the exhaust pulse hits the leak and reeking havoc on the O2. Not like open header oxygen sensor foul out, but depending on the severity of the leak.... Good luck.
