When I had my last tune up on my 2000 Ram 1500, the dealer changed the computer settings on the fuel mixture. Since then, my gas mileage is terrible!! The dealer tells me the computer cannot be reset to the orginal setting, so they are telling me there is nothing they can do to get the mileage back up. Is this true? Or is there someone who can reset the computer to the original setting?
fuelinjection

 

I am not sure about reseting the PCM, but why did they flash the PCM to begin with?