S3 Exhaust Flap


Registered User
Hi guys,

Can anyone tell me the positions of this flap at certain revs. Should it be open at idle and close up the rev range? Can anyone tell me how to test this?

The reason i ask is i have just revo'd my s3 facelift yesterday but now the manangement light comes on and shows fault code p0300 random misfires and p0303 misfire on cylinder 3 this only happens in 4th gear at around 6700rpm. I beleive others have experinced this problem, the car has only covered 3k so dont really see it being a injector issue? Any help would be great before i have to contact the dreaded Audi customer services.



I feel for you mate.
Judging by everyone elses experience it sounds like it's the injector. As that's what's happened to others - block on here had lot's of expereinces with his dealer around this very issue.
3000 miles or not, if the injector was already faulty/damaged the map may have just exagerrated the issue.

I'd maybe ask your dealer if they can check an alternative injector in cylinder 3 and see if that cures it?


Registered User
Thanks for the quick reply.

Yeah was thinking about swaping the injector to see if the problem moved with injector or stayed the same. I was hoping to flash it back to standard and then back to performance to see if this cleared it, but have to wait for my switch to come from revo.

Only thing that worrys me with going to dealers is if i put it back to stock and the problem goes away i take it they wont change the injector? Dont really want to tell them about the remap due to warranty issues.:(


Registered User

This is an electrical fault with the car that is related to the revision on the D/P as stated 100 times before the fault can be seen in stock mode during HIGH SPEED datalogging! The injector issue effected EARLIER cars before the d/p revision!

r18jsh feel free to give me a call in the office on 01327 301 901 and i can talk you through this....and anyone else for that matter!


VCDS Map User
Got this reply from my mod shop.

'I had a new S3 in last week from England it showed a misfire with Audi standard software & after the GIAC flash. I had a chap with GIAC & we tend to think it is the ABS & 4 wheel drive playing up on the dyno, as the car was perfect up the road.'

that throws some fuel in the fire does it not, or is it ********.


Registered User
I would have thought that the ESP should be switched off when the car is on the dyno. If that is the case then the ABS and 4WD systems shouldn't "play up" If the ESP was switched on and detected wheelspin/yaw etc then the ESP light would flash on the dash and the ECU would cut power. But would that show up as a misfire? I wouldn't think so.


Just Looking
VCDS Map User

I've looked on ETKA and I cannot see a revision of the D/P for the S3, when do you think it changed?


Registered User
Well tried sum injector cleaner this weekend but problem still re-mains. It does not happen every time though, its intermitent but only in 4th gear.

revocarl thanks i will give you a call in the morning regarding this.