Exhaust Popping/Backfire
Thread Starter
Burning Brakes
Joined: Feb 2007
Posts: 872
Likes: 0
Exhaust Popping/Backfire
I have a Callaway intake with Kooks 1 3/4 headers and Kooks Catt'd X pipe.
Installed the Corsa Pacecar Pro 3.5 exhaust and the car sounds amazing and nasty.
I have noticed now though on easing off the gas or in between shift shifts when clutching and
changing gears on the car it seems to pop alot on the exhaust.
Also noted that if give it the gas and rev to 3k and then coast back down in gear the car will
almost backfire.
Is that popping or almost backfiring normal with the Corsa Sports and or does the fact that the car
has not been tuned yet cause the PCM to run the car richer then normal that is causing this?
Will a dyno tune effect the sound output of the car on the exhaust?
Installed the Corsa Pacecar Pro 3.5 exhaust and the car sounds amazing and nasty.
I have noticed now though on easing off the gas or in between shift shifts when clutching and
changing gears on the car it seems to pop alot on the exhaust.
Also noted that if give it the gas and rev to 3k and then coast back down in gear the car will
almost backfire.
Is that popping or almost backfiring normal with the Corsa Sports and or does the fact that the car
has not been tuned yet cause the PCM to run the car richer then normal that is causing this?
Will a dyno tune effect the sound output of the car on the exhaust?
Melting Slicks
Joined: Nov 2005
Posts: 2,071
Likes: 0
From: clackamas oregon
sounds like you just described mine with its headers, x pipe, and corsa's
with corsa's only = pop, pop, pop on decel
corsa's and x pipe = pop, pop on decel calmed it down..... then one more install and
corsa's, x pipe, headers = pop, pop, pop ,bang
and happens in between shifts, slight decels in second gear coasting at 15-20 mph down hill. and other times that you would never expect. i figured it was an exhaust leak in the headers or the collectors. NOPE!! just lots more unmuffled flow. some day i will get the timing down and be able to scare the crap out of someone on purpose
with corsa's only = pop, pop, pop on decel
corsa's and x pipe = pop, pop on decel calmed it down..... then one more install and
corsa's, x pipe, headers = pop, pop, pop ,bang
and happens in between shifts, slight decels in second gear coasting at 15-20 mph down hill. and other times that you would never expect. i figured it was an exhaust leak in the headers or the collectors. NOPE!! just lots more unmuffled flow. some day i will get the timing down and be able to scare the crap out of someone on purpose
Last edited by rgtkst; May 5, 2007 at 04:29 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,470
Likes: 1,170
From: Dyer, IN
I know "backfire"is used rather loosely, but deceleration popping and a backfire are two entirely different things. A backfire is a serious problem, usually associated with timing, while deceleration popping is typically associated with an exhaust leak introducing air and igniting.
Thread Starter
Burning Brakes
Joined: Feb 2007
Posts: 872
Likes: 0
sounds like you just described mine with its headers, x pipe, and corsa's
with corsa's only = pop, pop, pop on decel
corsa's and x pipe = pop, pop on decel calmed it down..... then one more install and
corsa's, x pipe, headers = pop, pop, pop ,bang
and happens in between shifts, slight decels in second gear coasting at 15-20 mph down hill. and other times that you would never expect. i figured it was an exhaust leak in the headers or the collectors. NOPE!! just lots more unmuffled flow. some day i will get the timing down and be able to scare the crap out of someone on purpose
with corsa's only = pop, pop, pop on decel
corsa's and x pipe = pop, pop on decel calmed it down..... then one more install and
corsa's, x pipe, headers = pop, pop, pop ,bang
and happens in between shifts, slight decels in second gear coasting at 15-20 mph down hill. and other times that you would never expect. i figured it was an exhaust leak in the headers or the collectors. NOPE!! just lots more unmuffled flow. some day i will get the timing down and be able to scare the crap out of someone on purpose
is a AIR check valve issue, so checked the engine area out.
Found that the hose on the value had the clamp missing, dealer must
have forgot to put on after the header install. Was thinking that air
was leaking into the system and causing the pop's and backfiring.
I bought a clamp and fixed it and figured it might fix the popping
but no go, the leak was fixed because the Check Valve error is gone now.
Think this is just the way the exhaust is going to be.
As for the backfiring I think the lack of a good tune is the cause for
this, maybe the car is runnig a little rich, I dont have a wideband to
check it out.
Burning Brakes
Joined: Oct 2004
Posts: 931
Likes: 35
From: Rowlett, Texas
I had the exact same problem after installing an off-road x-pipe.
I have stock cast manifolds and Ti mufflers, and it popped so loud I thought it was going to rip a seam in a muffler. It only "banged" when I wound it up above 3500 and decelerated/coasted down.
Otherwise the exhaust note was exactly as I wanted it.
But, these "explosions" were absolutely unacceptable, so I bolted the cats back on - problem fixed. Now it has some of the normal gurgle/light pop on decel, but no cherry-bombs going off.
I lookled hard for any leaks or AIR-pipe issues before removing the ORP, but found nothing wrong. I can only imagine it must be even worse with headers, and I don't see how guys can run with non-catted exhaust and not get some of this horrendous super-loud popping. Sounds like big firecrackers going off.
DG
I have stock cast manifolds and Ti mufflers, and it popped so loud I thought it was going to rip a seam in a muffler. It only "banged" when I wound it up above 3500 and decelerated/coasted down.
Otherwise the exhaust note was exactly as I wanted it.
But, these "explosions" were absolutely unacceptable, so I bolted the cats back on - problem fixed. Now it has some of the normal gurgle/light pop on decel, but no cherry-bombs going off.
I lookled hard for any leaks or AIR-pipe issues before removing the ORP, but found nothing wrong. I can only imagine it must be even worse with headers, and I don't see how guys can run with non-catted exhaust and not get some of this horrendous super-loud popping. Sounds like big firecrackers going off.
DG
Thread Starter
Burning Brakes
Joined: Feb 2007
Posts: 872
Likes: 0
Yes I can imagine, have the Kooks pipe with cats, might be Random, or someone else? but with none it would be crazy.
I too get the mini backfires when going to 3k and decelerating again.
But I dont usually drive it that high in rpm and then coast back down again
so I am not worried.
I checked for leaks everywhere and fixed the fallen off hose clamp and
my car is clear now no PO1415 fault.
Figure a nice tune might change the exhaust sound a bit, will let you know.
I too get the mini backfires when going to 3k and decelerating again.
But I dont usually drive it that high in rpm and then coast back down again
so I am not worried.
I checked for leaks everywhere and fixed the fallen off hose clamp and
my car is clear now no PO1415 fault.
Figure a nice tune might change the exhaust sound a bit, will let you know.
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