I posted earlier about setting an SES light using the HPP 93 tuning and the GMS maf. It took about 30 miles to set the SES light with the tuning combo and the SES light went out about 30 miles after taking all the HPP tuning was out. I'm only using the raised shift points and firm shifts now. With the HPP 87 tuning and stock maf, my truck ran 0-60 in the 6.5 range. With the HPP 87 tuning and GMS maf, my truck ran 0-60 in the 6.4 range. With the HPP 93 tuning and the GMS maf, the SES came on after 30 miles, no 0-60 runs. Now with no HPP tuning (only raised shift points and firmer shifts) and the GMS maf, my truck is running 0-60 in the 6.3 range. It looks like the HPP and GMS tuning may fight one another, my truck really seems to be running well now. The rest of my mods are in the sig..
Jim

 

HPP3 and GMAS are bad mods together. Each leans out the truck and both lean it out too much and rob power. That's probably why you were getting codes. They may have been lean codes, which the pcm would clear after one of them was off and the truck wasn't lean. You're air injection/O2 sensor code could have been the O2 sensor going quirky b/c of the lean condition.