Anyone got any ideas on what is wrong with my 1999 S3 (APY 8L)? Above 5000 revs (all gears) it stutters badly and sometimes cuts out completely so that the ignition needs to be turned fully off and back on to reset things. EPC light comes on. Subsequent fault codes indicate abnormal MAF and Lambda readings. This is what it is not: MAF (I have tried 2 brand new ones, both Audi, 1 of which was sent back to Germany for testing and found to be fully functional); coil packs; plugs; throttle body dirty (cleaned); turbo intake hose (replaced with Audi part in case it was collapsing); dirty fuel or air filters; the cruise control I had fitted (problem remains when cruise disconnected). Without MAF connected it doesn't stutter but power reduced. I have been told that this is because disconnecting the MAF stops the engine recognising a problem and responding accordingly. The readings from the MAF and the Lambda have been checked by diagnostics specialist when car stationary and found to be within normal boundaries. Problem only occurs when engine under load, ie when on the road. Mileage 92000. I have tried higher octane petrol and Redex additive. I only use Esso petrol, no supermarket stuff. Cambelt changed about a year ago. Thanks.