I recently purchased the superchips flashpaq programmer. Does any know what kind of MPG gains I can expect on a stock gmc 4x4 with the DPF. Also will this programmer crap up the DPF? Thanks,

 

The Superchips should be safe for the DPF. I'm not sure about mileage.

 

I don't think it craps up your DPF, but if you drive it hard you will probably get a code (I forget which one). It just means (check the code to confirm) to get out on the highway and let it regen, once its finished the code will go away and you are good to go.

My truck does that with the PPE set on the higher settings if I am driving it harder then usual. Not often but it has happened 4-5 times over the past couple of years.