Right i was wondering if anyone can help as i feel like punching my car! the problem is that when its starts come under load (ie when the boost kicks in)it just misfires big time and the rev counter starts flicking all over place it also some times cracks a loud bang out of exhaust and the most annoying thing is,is that it does not do the problem all the time but most of it. i took it some wher and he checked every thing under bonnet and he says that it is deffo nout under there,also have had the ecu checked and thats fine.so any ideas would be really apperacited as im going mad