Craigito

So here are the symptoms...

Huge overboost under mild throttle application, then a loud jolt and then EPC light and NO throttle response (engine continues to idle however). Really only happens when the car is already moving.

I notice this overboost a lot when I apply even light throttle as the car is under engine braking at somewhat high RPMs (say as the rpms are coming down from 4k to 3k) and then even a light tap of the gas sometimes will pull super super hard and then it happens. It never happens when accelerating from a start. It seems if I go WOT it won't happen, it's the light throttle that seems to make it happen.

I really want to get this fixed before I sell the car. It's completely driveable and only happens intermittently, but it's not safe.

Ideas?

bschmidt1125

I don't have experience with this issue on my A4, but when the TPS went out on my old GTI VR6 (non-DBW) it was barely driveable. EPC refers to the drive by wire system, so I would probably start there first.