# Exhaust Popping / Backfire??!



## AlRadcliffe (Nov 14, 2007)

Over the last few days though it's been popping or misfireing, for example when I take it up to 2800-3000+rpm in 2nd gear & change to 3rd when I put my foot on the clutch it makes a loud pop, and some times it'll do it in the overrun when yu take yur foot off the throttle at 3000+ rpm.......I'm stumped as to what it could be.....








It does it when its warm 90c and it's got an aftermarket backbox on but thats been on for 2years and it's never done this before......
Any suggestions as to possible causes/solutions? 
Cheers
2001 150bhp 1.8T
Revo remapped


----------



## pherrera1.8t (Mar 30, 2008)

*Re: Exhaust Popping / Backfire??! (AlRadcliffe)*

i have no idea what's going on either. the same thing is happening to my 2000 jetta gls 1.8t as well and i hate it. but like u said it only happens when it's cold. i die a lil everytime i hear that dreadful noise!!!!


----------



## -Khaos- (Dec 22, 2003)

exhaust leak.
Get a buddy, stuff a rag into the exhaust tip, and give it some gas (just a little). Have someone under the car listening/feeling for a leak.


----------



## AlRadcliffe (Nov 14, 2007)

tried that mate, no leaks. anything else it could be? 
thanks


----------



## ulua4me2004 (Aug 15, 2007)

*Re: (AlRadcliffe)*

Mine started doing it when I changed to BKR7E's, also only when its cold. Once it warms up its gtg. I blame mine on bad 02 sensor, shes just running a little rich..... http://****************.com/smile/emthup.gif


----------



## AlRadcliffe (Nov 14, 2007)

whats the O2 sensor and wheres it located


----------



## DK_GTI_racer (Oct 4, 2007)

think ure car is runing to rich, its throwing fuel inside your exhaust, that ignites and make that popping sound...its unburned fuel making that noise....


----------



## AlRadcliffe (Nov 14, 2007)

ok thanks for yur reply, but how do i find out whats wrong with it, and stop it running rich???


----------



## ulua4me2004 (Aug 15, 2007)

*Re: (AlRadcliffe)*


_Quote, originally posted by *AlRadcliffe* »_ok thanks for yur reply, but how do i find out whats wrong with it, and stop it running rich???

Damn, is it that bad?? Mine only does it maybe once or twice. You need to scan your car for codes with a vag-com, post your codes here and let the resident experts help diagnose your car. http://****************.com/smile/emthup.gif


----------



## AlRadcliffe (Nov 14, 2007)

yer mate like most gear changes it does it! Don't have access to vag, gonna have to take it to the stealers and pay millions for a scan aren't i!


----------



## tyrantanic (Jun 14, 2004)

*Re: Exhaust Popping / Backfire??! (AlRadcliffe)*

hmmm... get used to it. My exhaust pops/gurgles all the time. I get worried when it stops


----------



## DK_GTI_racer (Oct 4, 2007)

*Re: Exhaust Popping / Backfire??! (tyrantanic)*

if u are runing rich on stock setup, it could be the course of o2 sensor, or maf gone bad...get to a dealer, and they often just scan the car for free..no worries on that part, if they say one of those things are a gonner, exchange them and u should be fine...there is nothing normal about popping and stuff, u don´t have to be so worried - it would be worse if the car was runing lean...it still not performing its best, and not to mention your mpg should be lower then normal...


----------



## fobyulous (Oct 7, 2007)

*Re: Exhaust Popping / Backfire??! (DK_GTI_racer)*

get a free scan at autozone


----------



## themachasy (Jan 28, 2006)

*Re: Exhaust Popping / Backfire??! (fobyulous)*

My car pops and backfires every so often and has for the past 5 years. No problems.
Try replacing the plugs. Don't bother with autozone.


----------



## DK_GTI_racer (Oct 4, 2007)

*Re: Exhaust Popping / Backfire??! (themachasy)*

No thats not right, his car has been runing fine with the exhaust he has, until he got revo remapped as i understand?...wich means the car now runs to rich....not something u should just say, ok the car is fine....no its not....maybe if he was pulling like 400whp and insane exhaust and stuff, it would be hard not to get it to make that popping sound, but thats not the case is it?....
Right now i have 3" straight thru exhaust with at the moment 14psi of boost and 283hp, i have no popping..so explain to me way this is normal?
before when i had Ko3 and 2,5" echaust i got that popping - and it was due to runing to rich.....


----------



## 20aeman (Jun 8, 2006)

If it's the tune, you can fix it with lemmiwinks.


----------



## AlRadcliffe (Nov 14, 2007)

lads it's had a remap about 40,000 miles about and it's done 60,000 now.....but it's been fine until last week.........so somethings obviously broken recently......seems to be slighty worse when cold......plus it's got the roughiest idle ever when it's stone cold!


----------



## pherrera1.8t (Mar 30, 2008)

*Re: Exhaust Popping / Backfire??! (AlRadcliffe)*

mine got a lil worse. so whenever i turn it on an rev it even a lil it pops. i die a lil every time i hear that noise!!!! so now i just let her be and let her warm up... i guess she has t get ready for sum action if u kno wat i mean!!!! lol


----------



## DK_GTI_racer (Oct 4, 2007)

*Re: Exhaust Popping / Backfire??! (pherrera1.8t)*

in worse case, your turbo could be broken, or loos in the compressor wheel....anyway it shouldn´t all of the sudden start popping...some people experience it when swithing to a big exhaust, but thats due to not having the car mapped with the exhaust, or trimmed by lW..anyhow..think something different could be wrong in your case, since u have droven so long with no worries...the cat could also be a gonner...i would take it to a stealer..


----------



## AlRadcliffe (Nov 14, 2007)

Thanks for your inpu mate, can the stealer check is the CAt's gone then? I don't think or at least hope it's not the turbo, as theres no loss of power...


----------



## pherrera1.8t (Mar 30, 2008)

*Re: (AlRadcliffe)*

mine still pops as well everynow and then. it has a 2.5" magnaflow exhaust and the cat was changed a long time ago. it was fine up untill a couple weeks ago.... don't kno wats going on...


----------



## DK_GTI_racer (Oct 4, 2007)

*Re: (pherrera1.8t)*

do u have a wideband kit installed to see if your runing lean or rich?...think you are runing to rich, or the compressor wheel in turbo is a bit loose, either one of them could be the answer......i have a 3" exhaust know and no popping what so ever,.......


----------

