My uncle has a 2003 4 door 3/4ton 4x4 6 speed dodge and he wants to get a lttle more power and gas mileage out of his truck without making the truck any louder exhaust wise. If he was to put a chip on his truck and leave the stock exhaust parts on will he have any problems?

 

depending on how much power he wants it shouldn't be a problem. remember when you start adding power it needs to breath in and out better. he should be ok with a small chip. the 03 and early 04's run cooler than the 600/610 motors. he can add an intake which will help too. tell him to get gauges so he can watch everything better

 

The only problems will be EGT's. The stock muffler is pretty restrictive, and will not allow the engine to cool as good as a high flow aftermarket muffler. As long as he gets guages along with this chip, and can watch EGT's, he should be fine. You do know that you can replace just the muffer with an aftermarket one, without replacing the whole exhaust. Cost...maybe $200 total ? Is worth it IMO