My 99 3500 developed a fuel leak at the fuel tank. Took it to the dodge dealer to have it checked(was unable to get down on the ground at the time). The steel lines coming out of the fuel moduel were rusted through. Had it replaced(very expensive). They recomended a fuel pump upgrade?? This moved the fuel pump from the side of the engine, back to the fuel tank. Ever since then my milage has been bad. Truck seems to run OK. Do you think they might have done some program update when they installed the new pump that might effect my milage?

 

it very likely you can call them and ask it should be in there records

 

....this is just a guess as many things can cause fuel mpg loss.


Part of the in-tank fuel pump install calls for a flash update to the ECM. IF your ECM had never been updated you now have more fueling in OD as there was a tsb back in the dark ages that covered a complaint of "lack of power while towing in OD". They had reduced the fueling in OD in hopes of making the trans last longer, but apparantly they "over-did" it and killed a bunch of power....anyways, they came out with a flash that made the fueling in OD/lockup the same as 3rd/lockup. More power.....more fuel. I remember quite vividly people reporting poorer mpg after this update was done.

....and NO, it can't be "un-done".

 

Could I get my mileage back with a Smarty or Juice?