It will set a CEL without a tuner but I was running the ATS tuner which is equivilant to the PPE and it will clear your CEL light when you install it. I dont mean to be pushy but, if your going to spend that money on PPE go with the EFI live hands down SO much better than a plug and play!
I never got a CEL with the above mentioned mods, it would set a soft code that was stored, but never tripped the CEL light. I guess some trucks do, some don't.