Warriorpluto
Full Access Member
- Joined
- Mar 23, 2017
- Posts
- 339
- Reaction score
- 153
I had the same problem even after putting in new acdelco spark plugs. The hottest my cats got on the highway were 1400f. O2 sensor voltage was good. No vacuum leaks. Still have knock retard every five seconds on the highway. I just used hptuners to pull timing on those spots for now until i can figure out what's going on. Always used 93