Ngk tr6ix by far. Don't fiddle with cat settings if it's still on the car.

Sure you could add about 2 gallons of e85 if not more butt most places are in winter blend so you can get away with a little more . Scanning is your friend.

I always recommend a couple things first

Tune the transmission take off dod. Disable tcc lockup to to 4th gear
remove all bank 2 b.s from the scanner.
Install catch can
get
trans cooler
Install shift kit if you want it to live.


No, 16s will not clear