I recently changed my spark plugs (FR6) and have noticed a very slight stutter in the exhaust note during idle. It almost has a very faint popping sound every now and then...sounds pretty cool...however I have no idea what it is? The car runs fine and there is no indication while cruising around, etc. The engine revs nice and smooth...it's just during idle when you can hear the faint popping sound. It's off and on.... sort of like... hummmmmmmmmmmmm...poppopopop.......hummmmmmmm....p opop...hummmmmmmm, etc. LOL!

Might this be a characteristic of the Fabspeed Super Sport exhaust? Or im wondering if there could be a very small air leak from where the cats hook up to the mufflers (fabspeed super sport). I have those vclamps cranked down, so I doubt it.

Any ideas what might be causing this?

 

Just want to add....

I installed the mufflers (from straight pipes) after the spark plug change and that's the first thing I noticed. Before I had a custom fab exhaust (ver8) and never heard that popping/backfire.....

Remind you...this is during idle...not while driving around and letting off the throttle...as I know the backfiring/gurgle is common with aftermarket exhausts.

 

Heya Bill,

All of my exhausts (not the ver 8) did/do that. I kinda like it too lol... Are you tips nice and black?

 

Nice and Black. Im not running as rich as you...but I get my fair share of black deposits all over the place! LOL!

Thanks for confirming above...

 

I heard that the ones that come directly from porsche are gapped correctly?

In any event, I would assume that if they were not properly gapped, the car would be running like crap. I dont have any problems with performance...just the very faint stutter at idle. This is a new exhaust (new as in recently changed), so Im not that familar with the sound at idle.

 

mine is 3 months old and has done this from the start; never thought much of it

 

Stock idle should be rock steady at 780 rpm. If it occasionally wavers ( dips to 700 and quickly recovers ) you have a misfire. Stock plugs can come with wrong gap if the plug were dropped at install or manufacturing - ask me how I know . Perhaps one of your ignition coils is not " snug" after the plug change. :

 

I believe it could be a slight misfire....however, performance does not seem to be affected at all?

What are the consequences of not addressing this "slight misfire" if any? I really dont want to reinstall the plugs again, however, if it's a must, i guess I have no choice.

 

I had the exact same problem on my 02tt. Took it to the dealer, who originally thought it was defective coils. They replaced all the coils, but the problem was still present. They next replaced all the spark plugs and now the car is running fine.

I had a similar problem on my Cayenne Turbo. I had installed an aftermarket exhaust and the car ran better than normal. After a few weeks, the car was not smooth at idle; always a little variance. Took the car to the dealer who had it for one full week and stated it was because of the aftermarket exhaust. Removed the exhaust and now the car runs perfect again. However, the exhaust was installed on a friend's Cayenne Turbo and he's never had a problem. Go figure...........