Cats off, running rich?
This is all that I have done:
Blackwing lid
Donaldson Air Filter
MTI Throttle Body
Smooth Bellows
BG Ram Air
LS6 Intake Manifold
Kooks Headers w/ EGR
True Duals X-pipe without cats
I'm not going to do anything else to the car.
You can get your VE & MAF tables retuned and that might help "some".
Rear O2 sensors don't control fueling.
You can get your VE & MAF tables retuned and that might help "some".
Rear O2 sensors don't control fueling.
I gained 11hp/11tq when I had the car tuned after my headers were installed.

