So I'm tuning a stock 09 gmc sierra 5.3.
Didn't touch the tune besides shutting on rear 02s because I put a wideband in.
Did a pull just got a starting point. Wot hit 9.5 to 8.9 don't understand why. Also had quite of bit of knock turned off cot and same thing. The truck has no codes
Why is it dumping fuel and getting knock
Lol sorry I'm still a noob thanks in advace.