No rough idle! It almost feels as if you've removed a bit of the power and torque you'd have in the lower third of the rev range with the stock manifold and added it to the top end instead, meaning things like low-rpm acceleration may require a tiny bit more throttle input. We've found this to be a lot more common on the manual, 2.5L cars (so something like a 2006-2007 C230) than the 7-speed cars or the manual cars with a 3.0L or 3.5L M272.

Intake Runner Flap code will be present. possible Lack of power and check engine light

Replacement