I've done the de-restrictions to the airbox, opened up my intake pipe (we dont have diesel vectras in australia) and drilled out the pre cat (what a mongrel of a job that was). Must say thats been the best bang for buck I've ever done.
But now after 6mths of trouble free thrashing (since the alternator regulator died) its giving me grief. It sounds like a Subaru and is running at about 1/2 - 2/3 power, cuts in and out from being good and not. I hope its not the coil pack again I already replaced that 2 years ago with a brand new genuine one. The engine light has only come on once for like 4 seconds. I suspect its running on 2 or 3 cylinders. Could it just be a dirty spark plug? they're quite new and genuine as well.
Any help apreciated.