# Popping/backfire after heavy acceleration?
**URL:** https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016
**Category:** NYSpeed Automotive
**Created:** [September 7, 2007, 5:30pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016 "2007-09-07T17:30:22Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@snowracer101](https://forums.speedlife.net/u/snowracer101)
#### Post date: [September 7, 2007, 5:30pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/1 "2007-09-07T17:30:22Z")
Just recently I’ve noticed my car has been making a rather loud popping noise after heavy acceleration.
It happens maybe 2-4 seconds after I let off.
It sounds like it’s coming from where the downpipe connects to the exhaust… But i’m not positive.
What should I check?
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### Author:  [@9ONA3OOZX](https://forums.speedlife.net/u/9ONA3OOZX)
#### Post date: [September 7, 2007, 6:23pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/2 "2007-09-07T18:23:09Z")
is it popping while in gear still, or are you clutching in?
whenever i’m at low RPM’s (2000 or less) and have the clutch engaged, and am just coasting…i get tons of backfires…ranging from barely noticable to gun-shot like…
it’s just fuel being dumped in the exhaust i would believe…and it’s not too uncommong for aftermarket exhausts with no cats and such…
backfire is bad when it does it while you’re on the gas…
but, if you’re still worried, check the full exhaust…and if you have the ability, check to see if you’re running rich at all…that might explain excess fuel… :gotme:
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### Author:  [@suppressive\_fire](https://forums.speedlife.net/u/suppressive_fire)
#### Post date: [September 7, 2007, 6:40pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/3 "2007-09-07T18:40:35Z")
is it a honda? lol jp looks like 90na300zx’s got it.
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### Author:  [@snowracer101](https://forums.speedlife.net/u/snowracer101)
#### Post date: [September 7, 2007, 6:46pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/4 "2007-09-07T18:46:52Z")
Yeah, it happens while still in gear, The car is running rich and is in need of a tune. I thought this is what was causing just wanted to make sure.
Thanks!
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### Author:  [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)
#### Post date: [September 7, 2007, 7:02pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/5 "2007-09-07T19:02:45Z")
FYI: if it’s happening IN the exhaust, it’s not a back fire, it called an “after fire”
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### Author:  [@Carnut](https://forums.speedlife.net/u/Carnut)
#### Post date: [September 7, 2007, 7:33pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/6 "2007-09-07T19:33:01Z")
Sounds like you may have an exhaust leak. Fresh air is entering the exhaust and igniting any unburned air fuel mixture left over from combustion. Have you revently done any work in that area? Did you maybe hit something? Check it out. 🙂
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### Author:  [@traumadog](https://forums.speedlife.net/u/traumadog)
#### Post date: [September 7, 2007, 7:57pm UTC](https://forums.speedlife.net/t/popping-backfire-after-heavy-acceleration/35016/7 "2007-09-07T19:57:22Z")
I get popping all the time when decelerating; guess it depends on what the engine controller does during “deceleration fuel cut-off” (at least that’s what it’s called with GM controllers). If it’s new though, it might be a bad injector… though that’s a guess.