I have got to share this with everyone who has a truck or car   Okay let me start with my 04 Dodge Ram 3500 5.9 diesel  about 2 weeks ago it started running very rough and I tryed everything that could think of to fix it ,fuel filter, air filter new fuel and fuel additive yes it needed all this but it still didn't run right so I ask a friend of mind what he thought...(mechanic)  he ask what the truck was doing, after I told him how it was running  he told me to go to the store ( NAPA ) and get some  MASS AIR FLOW SENSOR CLEANER   He told me to take the sensor out and spray this cleaner all over it until it was clean ... It took me longer to think about it than it did to do the job ... And I have got to say my truck has never run better I just can't believe the difference in power and mpg's I'm getting now.      This is a very easy job to do, this sensor is located on the AIR INTAKE hose (easy to find) just unplug it take 2 screws out ( Dodge trucks) spray this cleaner on it and you will not believe the difference...   I was told this sensor controls the AIR & FUEL for the engine , I'm not really sure of all it does and how it works but My truck run like a new one .  You might want to try this on your truck it worked for me.......  11oz. can $6.95  time to do the job 15 mins.