the best thing you can do for cheap, is to open the air box, pull out the trumpet thing and buy a decent cotton air filter, ie k&n. then go for a decent exhaust system. to be honest you won't get any huge power gains (if any) but you may get it back to its standard figures!! it'll be worth doing though so don't think i'm trying to be negative but often people put on an exhaust and claim 5-10 bhp gains when in reality its nothing like it, maybe just a better response?