i have a 07 3500 with the 5.9 6 speed manual with exhaust brake 162000 miles . it seemed all at once i lost fuel mileage and it doesnt seem to have the power it did at take off. and i have noticed some black smoke sometimes and its on the fender and bumper. i have changed oil oil filter fuel filter and air filter everything seems the same . i pull a enclosed trailer everyday. any help would be great thanks

 

Anything else? Engine noise? Harder to start?

 

starts fine everytime. the engine noise seems a little louder in cab. it seems like there is something holding it back runs great kinda like driving with the parking brake slightly pressed

 

injectors maybe. just a shot in the dark. take it to the dealer and scan it. they should do it for free. check injector balance rates while its hooked up. let us know

 

checked local dealer were i bought truck used $225 to check injectors but im suppose to drop it of monday morning thanks

 

damn thats a rip off my guy at the local dealer checks all that stuff for free. anyways i hope you find your problem.

 

i used a snap on modis today an diasbled the injectors one at a time an it seemed that a couple of the injectors didnt make as big of a difference as the others. some were very noticable an some you could barely feel any change

 

took truck to dealer and they reflashed computer seems everything is fine again cost about 75 dollars thanks for the help