Should a standard Cupra pop from the exhaust?

[SeanyK]

Hey folks, few things being done to the Cupra next week, but driving Pulsebass's Cupra, we noticed it didn't pop much when letting off the accelerator (His is MK3, Scorpion Cat back, revo'd FMIC, Forge TIP, Dynatwist) whereas mine is pretty much standard bar a Scorpion cat back and Jetex filter.

I noticed if I accelerate hard and then let go off pedal it will pop a few times from the exhaust, whereas his doesn't? Not loud bangs or pops, but just pop's i'd expect from a mapped car...

Surely it should be the other way round as he's running much more power?

I've checked for overfuelling but no fault codes show on VAGCOM, even though my car does feel juddery on the pedal when accelerating at low speeds (it also seems to if I put foot down then at about 2.5k-3k revs up and down for a second, which is noticeable, but then goes up the rest of the revs fine, i've put that down to the clutch though (which is being replaced next week).

 

[s1l3nc3r]

have u got middle box..? My mates got same custom exhaust as me apart from no middlebox and hers pops she at stage 1 revo. ive still got my middlebox and mine doesnt pop im getting my middle box out hopefully next couple of days ive got standard map, forge tip, cat-back exhaust, jetex filter, and turbosmart dv. Will let you no if i get anything from it hoping i will tbh.

 

[Sandy1985]

my cupra used to pop a bit, i had a remap and supersprint cat back, but after i put a forge split-r and blueflame downpipe and cat on it verry rarely pops... i might put the original DV on to see if it comes back.. ive always wondered why it stopped popping, now ive thought about it i think it may be the DV..

 

[SidewaysCupra]

my cupra used to pop a bit, i had a remap and supersprint cat back, but after i put a forge split-r and blueflame downpipe and cat on it verry rarely pops... i might put the original DV on to see if it comes back.. ive always wondered why it stopped popping, now ive thought about it i think it may be the DV..

DV wouldn't affect anything to do with the exhaust. Probably the cat or downpipe. Mine is running custom code stage 2 and rarely pops. I see it as a good thing. "Popping" is usually unburned fuel igniting in the cat or downipe. A sign of running a bit rich.

 

[SeanyK]

have u got middle box..? My mates got same custom exhaust as me apart from no middlebox and hers pops she at stage 1 revo. ive still got my middlebox and mine doesnt pop im getting my middle box out hopefully next couple of days ive got standard map, forge tip, cat-back exhaust, jetex filter, and turbosmart dv. Will let you no if i get anything from it hoping i will tbh.

Good point mate - answer is I don't know lol! I'll have to wait til it goes on the ramps this week to see what is under there, there is a receipt for a Miltek downpipe but according to the dealer I bought it from, it was not on there - also, Scorpion exhausts don't fit Miltek downpipes to my knowledge, so unless its gone;

Miltek Dpipe - Standard cat - scorpion cat back

I doubt i've got the Miltek downpipe, but then why have a receipt for something thats not there! I will see what I find when it's on the ramps!

Mind you, mine did have 'APR Tuned' on the back - and was standard mapped!

 

[s1l3nc3r]

ive heard those apr tuned stickers are goos for 10bhp+ well had my middle box taken out earlier still no pops as of yet but sounds very much more like it wants to havent really had a chance to let it go yet because of traffic. defo louder nice sound though.... Im not sure on the miltek d/p could of made it fit maybe is it defo a standard cat and not a miltek d/p and cat.?

 

[SeanyK]

10bhp at least!!! My car has been so much slower since I took that sticker off

I'll check this week on the ramps, i'd imagine it would be miles louder though if it had sports cat and downpipe on - I might be wrong, but pulsebass has the same exhaust system and his car is the same sounding, only difference is his is AQX mine is AYP engine.

When he took his ages ago to big boys toys (now AMD) they said the Scorpion exhaust he had couldn't fit on to a miltek cat / downpipe. But as you say, sometimes these things can be made to fit.

On a side note - disconnected the MAF just now, it drove exactly the same, if not a little smoother as it does when connected ... Is that right???! (It was actually popping a bit at idle with the MAF disconnected as well).

 

[warren_cox]

Wouldn't a car 'pop' due to an overly rich fuelling mix (unburned gases getting dumped into the exhaust)? Shouldn't make any difference what exhaust you are running should it, other than I guess a louder exhaust would accentuate the popping sound?

 

[s1l3nc3r]

If its driving smoother with the maf disconected then thats normally a sign the maf on its way out. I think that can cause a bit of overfeuling aswell which seems the case if ur popping slightly at idle.! Run some feul and maf logs on vag-cam if u can see if it shows up any possible problems. There was a thread not so long ago about car being jerky on lift off no codes but logged the maf and it came back with possible problem which could explain ur judder in low revs aswell.

 

[SeanyK]

Heres some information from VAG COM logs the other evening, all looks fine in terms of g/s...

 

[SeanyK]

Just thought i'd update this thread - it still pops! It's been remapped, and it will pop cruising along in 3rd gear, as well as if I drive it fairly hard and then let it and let go of the throttle.

I am a bit paranoid it's running too rich, but im not really sure how i'd measure that... The MAF seems OK as do the coilpacks, sparkplugs were changed 100 miles ago (NGK PFR6Q's).

Im gonna replace the coolant temp sensor, just because I have a green topped one from when I used to own the same model of car.