VW Mk6 gti rough idle + misfires & CEL code: P0506 (Idle speed performance lower) I ordered a new PCV valve hoping it resolves the misfires, but I stumbled upon this near
SUPERCIRCUIT Exhaust Pro Shop: VW Golf Mk6 GTI Downpipe
Solve Your VW MK6 GTI 2.0T TSI Misfire and Check Engine Light – ECS Tuning