1G Problems & Issues
I have an 07 RTS with 62,000 miles on it. It runs just a bit rough at a light while in gear. Not so much while in park. I have noticed a drop in MPG. From 17 down to 13.5. I replaced the plugs with NGK Laser Iridum,(and had to re torque after 2 weeks), cleaned the throttle body, and ran injector...