AFR wrong? Something else?

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Apr 18, 2005 | 11:46 AM

ArmyVette

Thread Starter

Le Mans Master

Joined: Sep 2003

Posts: 6,386

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From: Just a little outside San Antonio, Texas

AFR wrong? Something else?

When my MN6 is decelerating, I get this popping sound out of the exhaust. Didn't have this with my A4 coupe. Had the Corsa system changed over when I bought the Vert so they are running the same exhaust system.

The popping isn't loud like the backfires I have heard on other cars (not mine

).

I was wondering if perhaps the AFR was wrong and might need adjusting (via dyno).

Or could it be something else? Any suggestions/ideas?

Thanks!

Jeff

Apr 18, 2005 | 12:41 PM

WKMCD

Race Director

Joined: Dec 2004

Posts: 13,760

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From: Haymarket VA

Do you have the X-pipe. That helps. I have the Indy's on my M6 and they do pop and spit on decelerationeven with the x-pipe. I seem to get less since the headers went on over the weekend but it still happens. I don't think it's a factor with the A4 because you basically free-wheel when you let off the gas. Tuning may help but from what I hear it's still going to happen to some degree

Apr 18, 2005 | 12:56 PM

ArmyVette

Thread Starter

Le Mans Master

Joined: Sep 2003

Posts: 6,386

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From: Just a little outside San Antonio, Texas

I do have the Corsa X-pipe but what you say does make sense. With the A4, I'm pretty much free wheeling and the RPM drops faster. With the MN6, I'm using engine compression to assist with braking so that might be causing it.

Anybody else have an idea about this?

Apr 18, 2005 | 01:08 PM

phils C5 vette

Le Mans Master

Joined: Nov 2003

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From: Tampa Fl

St. Jude Donor '12-'13-'14

I have an X- pipe and if it helps, its not much.
about as much as the throttle by pass helps

Apr 18, 2005 | 01:23 PM

ArmyVette

Thread Starter

Le Mans Master

Joined: Sep 2003

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From: Just a little outside San Antonio, Texas

OK, from the two responses received above, I understand that these popping sounds are normal.

Right?

I have to ask because this is my first MN6 Vette.

Apr 18, 2005 | 01:52 PM

HP_Addict

Melting Slicks

Joined: Apr 2003

Posts: 2,285

Likes: 16

From: Nashville TN

Yes the popping on decel is normal. Sometimes it can be tuned out. Also an exhaust leak where the cat-back bolts up can contribute to it. Learn to enjoy the popping.

Apr 18, 2005 | 07:26 PM

mld45acp

8th Gear

Joined: Sep 2003

Posts: 8

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From: Indianapolis IN

I am running the Corsa Titanium Street system with the Corsa H pipe. Have had the popping since the install. This is normal.

Apr 18, 2005 | 08:44 PM

3XBlack6spd

Drifting

Joined: May 2001

Posts: 1,770

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From: IL

Poping sound is normal (and kinda cool) on a 6 speed, it is as mentioned before, becasue the RPM's don't drop as fast as an A4..if you push the clutch you won't hear it...a X pipe will definately help.