Guessing PCM Code?

[Power Hungry]

If there is a Glow Plug Control Module (GPCM... It's a little aluminum box with 2 square plugs on it) on the passenger valve cover, it's a California truck. If there are two Glow Plug Relays (they look like starter solenoids, with one actually being used for the Air Intake Heater) then it's a 49 State truck.

When you order an FU kit, you have the choice of what files to put on the chip. You can always remove the chip from the ECM to go back to stock, just make sure the key is in your pocket or in the back seat. That's the only safe place for it!