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Mar 2, 2008 | 08:58 PM

prowan

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Staging Lane

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From: East Tennessee

POST LT Header Install Questions

Well, just finished my LT header install and I'm about to burst with excitement. I went with Pacesetter LT's and 2 each, 3" High flow Magnaflow Cats (I know.. I know.. most of you all would have left them off, but I was worried about possible inspections). Anyway, I fired her up and drove home and initially the wideband acted real erratic.. My first thoughts were my Long Term fuel trims need to re-learn the extra air that comin in due to the easier flow. I plan to do some tuning tomorrow with HP, but wanted to ask the veterans if there is anything I need to look out for. When I drove home, I was real easy on the car but I did give a little power to see the differences. The throttle response seemed great. When I gave it some power I got a backfire or two. Is this common right after an install?? Will this straighten up after I adjust the VE tables and MAF?? Is there anything I'm overlooking or need to look for when I tune tomorrow?? Thanks so much in advance, you all are incredible help!!

Mar 3, 2008 | 09:02 AM

prowan

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Staging Lane

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From: East Tennessee

Anyone have any ideas??? It was popping/backfiring this morning?? What causes this??? HELP!!!

Mar 3, 2008 | 09:11 AM

transamws6_97

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check and make sure your header bolts are still tight. Mine came loose after a few days and caused my exhaust to have small pops when it was cold outside. Other than that it shouldn't be backfiring...My car acted exactly the same except it was very sluggish down low until I got my tune. Hopefully the tune fixes it for ya

Mar 3, 2008 | 09:33 AM

tylerdj

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Have you driven it very long? Like you said the PCM has to learn how to compensate for the increased exhaust flow and just doing some cruising around could help it out some.

Mar 3, 2008 | 12:36 PM

00cls1camaross

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Check your spark plug wires, it is possible you didn't pop them in or you damaged a plug. I didn't really need much tuning after my LTs, ORY, and Fast intake.

Mar 3, 2008 | 08:17 PM

badpewter-z

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From: RI

do you have the cats just hanging off the headers and no y or cat back? if so that would be one of the main reasons

Mar 4, 2008 | 11:40 AM

prowan

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Staging Lane

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From: East Tennessee

No... I have the cats tying together in a 'Y' fitting and from there back, it is stock (except the muffler is a Flowmaster 40). In my original post, I described the sound as a backfire, but to be more descriptive it sounds like a 'popping' noise. This only happens when the car is under a load and I'm giving it a lot of peddal... It does not do it when I let off the gas and decellerate.. Could this be a miss?? I'm gonna ask this question also in the main forum. Thanks for the replies.!!