hi guys ,
i have the G coupe 03 auto
K&N air-intake
underdrive pully
spacer 5/16
buddyclub


before two weeks i put the JDM headers with the test pipe and i reset the ECU.


the car now become heavy,the power is down

i do not know why ???
maybe the Y pipe because i did not change it
maybe it needs the reflash ??
guys please help me

 

any help

 

do a search on plenum spacers, some people had problems with it. Something about not evenly tightening the bolts or if not that, easily breaking one of those bolts. I'm not exactly sure, i just read it somewhere.