right ive got myself a budget from the end of next month i will have £1k to spend on engine mods, ive only owned the car a few weeks but already got a cat back exhaust system and should have the airbox de-restricted and pre cat out by the end of the week(from good advice ive took from this site), the 1k im spending will be just in parts, the fitting i will take care of after, whats the best parts to get first? any advice would be appreciated, i have a vectra 2001 2.2sri, thanks