Maintenance, service, and repair
Good afternoon,
I own a 2015 WRX, Stage 2 (Cobb 3" exhaust, OTS Stage 2 Map using Cobb V3 Accessport). I've always monitored regular feedback knock, it comes and goes (the high negatives). I've driven this car (stage 2) for months now, I've just changed the oil and had a friend who is a...