[SkullV]

Hey guys, I have noticed that lately my exhaust sounds raspier on decel then it used to, especially RIGHT after I push in the clutch. Here are a few videos to show you what I'm talking about. The first one is from about a year ago (skip to 30 seconds in) and the second one is from today:

Is it all in my head or is something going on with the car?

 

[darkman]

It sounds different to me, but I do not know what it could be other than gradual deteriotation of the cats/resonator/mufflers.

 

[GNENSEC]

Had the same on my M5 granted different cars, but it was the CAT deteriorating, don't know as much considering I'm a newbie but, it may also be baffles in your mufflers going.

 

[SkullV]

Hmmm....maybe I should just gut the cats...

 

[darkman]

Hmmm....maybe I should just gut the cats...

Those cats may be self-gutting - just be patient.

 

[c4ss]

Also agree on the cats. After I got my cats replaced with high flow ones on my GT, they got considerably louder as time passed. I wouldn't worry about it though, the car sounds good :thumbsup:

 

[whisler151]

Wow...almost the same set up and our cars sound WAY different!

I too have more popping as time goes on.

 

[mpunklil]

sounds fantastic to me

 

[Twitch]

You better get under there, and take a look. Sounds like one of those corsa losers swapped out your Magnaflow while you were hungover one night.
Just sayin.....

Hey, isn't the popping a condition of a lean mixture? And doesn't that kill your cats, if you have the rear O2s turned off?

 

[SkullV]

You better get under there, and take a look. Sounds like one of those corsa losers swapped out your Magnaflow while you were hungover one night.
Just sayin.....

Hey, isn't the popping a condition of a lean mixture? And doesn't that kill your cats, if you have the rear O2s turned off?

From what I understand popping is a side effect of swapping out your resonator for an x pipe...

 

[Twitch]

From what I understand popping is a side effect of swapping out your resonator for an x pipe...

Very much doubt that. I have an x pipe with no popping at all.
I could be wrong (I'm certainly not one of the "smart" guys). But back in my bike days, when you change the exhaust, sometimes you get the popping on decel. Change the jets to richen up the mixture, and the popping was gone.
It doesn't sound bad, but compared to what it sounded like last year, I'd be pissed.

 

[SkullV]

Very much doubt that. I have an x pipe with no popping at all.
I could be wrong (I'm certainly not one of the "smart" guys). But back in my bike days, when you change the exhaust, sometimes you get the popping on decel. Change the jets to richen up the mixture, and the popping was gone.
It doesn't sound bad, but compared to what it sounded like last year, I'd be pissed.

Yeah, I do remember adding a little fuel to the mix being the solution to reducing the popping...I am less concerned with the popping then the terrible sound it makes RIGHT after you let off the gas though. From what people are telling me its the cat's breaking down

 

[CTSV_510]

Might you have any exhaust leaks that are changing the flow of exhaust?

I thought popping was from un-burnt fuel (rich mixture)? I thought the tuning solution to getting rid of the pop was removing fuel on decel?

 

[SkullV]

Well does anyone have any ideas of what to do about it? Would gutting the cat's work? I have heard that gutting them decreses velocity and is a no-no, and that I should either run a straight pipe through them or get test pipes made.

 

[NormV]

Just the opposite. DFCO or decel fuel cut off is a major contributor to popping.


Ted, you'll have to pull the exhaust to take a look at the cats.


Norm

Might you have any exhaust leaks that are changing the flow of exhaust?

I thought popping was from un-burnt fuel (rich mixture)? I thought the tuning solution to getting rid of the pop was removing fuel on decel?

 

[lollygagger8]

If you don't care about it stinking, gut the cats. If they're going bad, might as well speed up the process. I didn't think your car sounded bad though. The only thing different is your tune since the last video, right?

Tony & Norm are right: popping on decel is because of lean mixture. Tuners add more fuel to get rid of it.

 

[SkullV]

Yep..a tune and about 7,000 miles (only about 700 of which are on the new tune)

 

[CTS-Voodoo]

My V always sounds like that lol. Its raspy as hell on decel. I dont care, thing sounds mean as hell going forward. Yours pops more cause the tuner probably left the decel curves a little rich. Its no big deal, you can tune it out if you really wanna.

 

[c4ss]

Who tuned it? Once I got my W4M my popping was gone.

 

[SkullV]

Ron at Pro Dyno Tech in Crawfordsville, IN. I love the tune, and it made the car feel 100x better then the first tune...but now I have this damn noise (it was happening before the second tune but it has been getting worse)