stillen exaust, louder engine?

[ElDiablo]

Noticed after i installed my stillen muffler, the engine is louder and maybe even knocks now. Anyone exsperiance this as well. Talked to a guy that knows a guy and said its just coiencadence, that im using cheap gas. So im going to try high octane.

opinions?

[CodeRed]

Installing an exhaust system, and in the case of the stillen only an axel back you shouldn't experience and knocking...

That could be bigger problems. Check your oil, run premium fuel, and bring it to the dealer if it persists.

under NORMAL conditions when the engine is cold you will hear come clanking and that's from the valves and is completely normal (on this motor at least) and the clanking should go away when the motor is fully warmed up.

[feloniousmonk]

Bad gas will do it. Bad O2 sensors in the exhaust system will do it too. Keep an eye on it and maybe have it checked to see if it's running lean. Otherwise, don't rev past 3k rpm until everything (oil/water) is up to normal operating temps.