Bad exhaust note after spark plug change - Northern California Ford Owners

This is topic Bad exhaust note after spark plug change in forum Tech Talk at Northern California Ford Owners .

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Posted by RSA-Mustang (Member # 11540) on :

Just changed spark plugs earlier today with motorcraft plugs on an 02 GT. Reasons were that I last changed them 50k miles ago and now car was beginning to misfire (very few times) and the car wouldn't respond under full throttle in all gears. Problem I have now is that no more misfires or lack of acceleration but the car does have a REALLY bad exhaust note after I drove it five miles. I did take it out around the neighborhood after the install and car responded well but an hour later I drove to the store and the thing sounds similar to a V6 with a very shitty exhaust job. My current setup is stocks headers. Magnaflow tru x catted pipe, bassani cat back with magnapaks welded in. I have zero white smoke and no lights on in the dash. What could possibly be the problem?

Posted by Bullitt1080 (Member # 11689) on :

Check ur spark plug gap. Make sure they are all at spec.

[ 2014-03-02, 11:36 PM: Message edited by: Bullitt1080 ]

Posted by Flatline (Member # 12081) on :

Agreed. Check plug gap and make sure boots are seated properly on plug.

Posted by dohcfox (Member # 12829) on :

Make sure you have the plugs tight. Could be compression pushing thru the plugs from loose plugs. Also no anti sieze on the plugs. They want to back out all the time on their own.

Posted by red5o (Member # 12651) on :

quote:
Originally posted by Flatline:
Agreed. Check plug gap and make sure boots are seated properly on plug.

Posted by RSA-Mustang (Member # 11540) on :

Sorry I should have mentioned I did use anti seize. Didn't check gap before because plugs are ford spec but I will double check them and the boots.

Posted by MaK_1967v8 (Member # 12187) on :

I don't care who says what about a "factory gap" You check those suckers before you slap them in. a gap tool is maybe a couple cents short of 2 bucks, and its an extremely important tool.

+2 on gap.

Posted by NEIGHT (Member # 8741) on :

quote:
Originally posted by RSA-Mustang:
Sorry I should have mentioned I did use anti seize. Didn't check gap before because plugs are ford spec but I will double check them and the boots.

There's your problem. ALWAYS check the gap before installing.

Posted by RSA-Mustang (Member # 11540) on :

Thanks for the advice. Car runs better now, a few plugs had gaps that were too small.

Posted by Beastly GT500 TVS (Member # 9723) on :

Lesson learned always check gap

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