seems to run fine and revs fine wen just sat there but wen i drive it theres no power,sounds like its missin and wen i let off de power i get a bang out the exhaust any ideas?

 

check ur coil, plugs, leads, the bang cud be unburnt fuel leaving chamber down exhaust

 

i av checked all that think it might b air mass its got a orange label air mass on it n a standard sti ecu the last owner that had the engine was runnin 380 bhp so gonna try that now

 

yeah maf can cause loose of power big time, so can failing fuel pump, also check all vacuum pipes etc for any holes, not sure what inter cooler u have, but check all joins in there also, if fmic, they look clamped but can be loose.

must have a fair spec for 380bhp.