I'm working with a '07 Silverado E38 (OS 12614088). When the scan first starts I see "good" Commanded AFR. But after about 4 seconds it suddenly jumps to 29.36 (twice 14.68). At the same time Injector Pulse Width jumps from 234 mSec (an impossible number) to 456 mSec. I'm using E38AFRATIO_DMA and GM.IBPW1 & GM.IBPW2, same PIDs I use with a '06 Z06 (OS 12605732).

By the way, thanks to Dragframe's " Interesting Issue: MAF failure = Idle tables ignored. Cant tune VE because of it" thread! Same year / OS. I saw the same MAF problem. That post helped me understand why I could not tune the idle.