Hello, I have a 1.8T chipped with apr, apr r1 and techtonics exhaust with labree highflow cat with 113,000 kms.
The problem I have with my car is at normal driving it shows no signs of problems. it is when i open her up the problems appear.
when i go into full boost it seems to misfire, and then boost falls off to about 5 psi, the odd time it backfires. I am out of ideas as I have replaced all spark plugs to ngkbkr7es gapped at .028 , replaced all 4 coilpacks, cleaned the maf and I get no codes on my vagcom either.
any help would be great.
Thanks for your time
Sean

 

I am having this same problem and I cant figure it out. One of my friends told me it could be the fuel filter being clogged or fuel pump not efficient enough for the chip but I'm not quite sure. Mine seems to do this backfiring/misfire as soon as my boost reaches about 12psi. If you find out any more information let me know. I have also changed my coil packs, plugs ngk gaped at .028, fuel filter, cleaned maf. same problem...

 

do you have a cel?

 

You should both test the ignition control module.

DIY test of power output stage/ignition amp module N122 (long & BWW) - AudiWorld Forums

 

its not the icm. my car runs perfect until i get to about 11psi then this backfire/misfire occures

 

Try dropping the plug gap to 0.025". This works for some people.