Just put a new Borla exhaust and high flow cats on 03 g35 sedan but seem to be having throttle response issues (lagging until higher rpm) and a slight sulfer smell ( surely the new cats aren't bad) Looking for any and all suggestions. Thnx!

 

probably need a tune.

 

Sulfur smell is ALWAYS the cats. I'd call whoever you bought them from, good chance you got defective units.

 

Or what I'm thinking is the OP got a new exhaust and it's going wide open throttle everywhere?

 

Lol....not hardly. Turned out to be a misfire on #5

 

Cats are good. 430-465 degree operating temp on both. CEL indicated a misfire on #5. Thnx for the help!