Got a 04 5.9 white smoking like crazy and backfiring at around 1200 to 1800 rpm. You can hear it backfiring in the exhaust right where the down pipe and the exhaust clamp go together trucks maintained on a regular basis never dogged on. We had it n the shop for about a month and a half working on the problem changed sensors out fuel pump ect.. still same problem. The shop to it to dodge and they said it was throwing a computer code saying the computer had a glitch in it dodge fixed the problem now more codes comeing up and still doing same thing. Anybody delt with this or know anybody that has had this problem??? Thanks

 

Bad injector maybe a burnt valve too! Scary the dealer didn't run an injector test!

 

Try this for some methodical diagnosis:

http://stuff.is-a-geek.net/OnlineDoc...diagnostic.pdf

 

Can't fig it out cause it only does it sometimes not everyday yesterday it was fine no smoke or backfire at all and today backfire and smoke again.