Well i recently got a 05 evo rs used from a kid that doesn't know anything... he says that he put evo 9 spark plugs in it and it started knocking... But when i got the car there was no knock... what happens is that the car idles but when you got to drive it as soon as it hit some where around 3k to 4k it studders and sounds like its missing real bad...makes no power what so ever... checked for boost leaks up to 20psi... had the dealer check the coils the said they were good i also went home and tried to check them myself but not to positive how... put a brand new set of plugs in it... took the valve cover off to change the spark plug seals and the valve cover had a crack in it... what do you think my problem is... any help is appreciated

 

I'd change plugs back to OEM spec VIII ones and reset the ECU. Worth a shot.

 

+11 ^^

 

make sure that the stock ecu rom is flashed in there and check again