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Car runs bad after header install...

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Old Sep 30, 2010 | 12:35 AM
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Default Car runs bad after header install...

Just installed pacesetters, y pipe, and magnaflow cat at the back of the y pipe going to the stock cat back with a hooker muffler

I know I have some small exhaust leaks that need to be fixed with some band clamps, but the car is popping and backfiring and it feels like I have a miss at idle

i'd assume that exhaust leaks would make the car run a little funky

does this sound like something stupid like a cracked plug? because i'm pretty sure there's a small crack somewhere on of em

or is there something else going on here?
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Old Sep 30, 2010 | 02:58 AM
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I'd say you might want try getting a tune-up and a tune.
A tune-up being new plugs/cables and tune being on a dyno.
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Old Sep 30, 2010 | 05:22 AM
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check ur spark plugs and wires, check spark plugs gap, make sure there is no spark plugs crack and check if the wires are connected good.
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Old Sep 30, 2010 | 07:17 AM
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Originally Posted by Engine_HP
check ur spark plugs and wires, check spark plugs gap, make sure there is no spark plugs crack and check if the wires are connected good.
Exactly, start here. You removed and messed with all that **** and it could be mutliple possibilities.
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Old Sep 30, 2010 | 07:19 AM
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Could just be a loose spark plug wire.
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Old Sep 30, 2010 | 08:18 AM
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Originally Posted by Element
Could just be a loose spark plug wire.
This is my guess.
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Old Sep 30, 2010 | 12:41 PM
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i found one bad plug, it runs a little better but there's still a miss at idle... can an exhaust leak cause a miss?
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Old Sep 30, 2010 | 12:58 PM
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x10 with the plugs and wires.

And exhaust leak would cause a ticking sound for a primary leak and a hissing sound for a collector leak. Shouldn't cause a miss.
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Old Sep 30, 2010 | 01:05 PM
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maybe you cracked a spark plug upon header intallation?
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Old Sep 30, 2010 | 01:06 PM
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maybe your car is ghey?
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Old Sep 30, 2010 | 03:20 PM
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i forgot th check the coils one time lol running on 4cyl it still got sideways
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Old Sep 30, 2010 | 04:08 PM
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Originally Posted by CarAteMyMoney
i found one bad plug, it runs a little better but there's still a miss at idle... can an exhaust leak cause a miss?
Replace them all...

I had a similar problem, and inspected all of my plugs. They looked to be fine, so I reinstalled them. My car was still backfiring and popping like an Uzi. I tried all kinds of things, but finally bought new plugs which solved the problem.

There had to have been a hairline crack on one of the plugs, but I never found it. They were all gapped properly.

Its easy to damage the plugs when you do a header swap.
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Old Sep 30, 2010 | 04:11 PM
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Originally Posted by smok'nZ
i forgot th check the coils one time lol running on 4cyl it still got sideways
same **** happened to me. I was like holy hell the car sounds mean as hell!! lmao!!
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Old Sep 30, 2010 | 05:05 PM
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plugs and wires
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Old Nov 25, 2010 | 06:57 PM
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whoops - turned out to be not 1, but 2 bad plugs... with the 1 new plug it ran better but there was still a slight pop at high RPM.. now the car runs like a champ, feels ridiculous!
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Old Nov 27, 2010 | 03:52 AM
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Do plugs and wires just incasecuz it could be one or the other, I had a wire that looked fine but was actually crap just couldn't tell.

Also check all your vaccum lines unless you did race style headers, then check to make sure all your air and egr stuffs blocked off or taken out.
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Old Nov 27, 2010 | 10:56 AM
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you may wanna get it tuned as well if you havent done so
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Old Nov 27, 2010 | 11:06 AM
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Any time there is unmetered air pulled in front of the o2's the car is gonna run shitty and rich. If I was you Id jus replace the plugs and fix the exhaust leaks.
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Old Nov 27, 2010 | 05:07 PM
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i did 8 new wires and plugs and had the exhaust fully welded, no more band clamps...... she left about 150 feet of rubber without the spark breaking up and idles perfect now
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