Hi, I have had a new trip computer instaled and it is not giving me the excact milage I can go to the next fill up, is there a way to reset it or is there something else I have to do, the old one was working right but it did not light up that is why we had it changed, any idea's please.
2004 6lt diesel crew cab lariat.

 

I don't have a trip computer on my truck but most people refer to them as a "lie-o-meter" and report that the fuel mileage readings are not accurate when compared to hand calculations.