I have a 2002 Dodge Ram 2500 with a 5.9L Gas engine. A month ago my crank position sensor went out , while having that replaced I had a new cap rotor wires plugs and Injectors installed . Since I had this work done I keep getting multiple misfire codes. At idle it is rough as hell but upon acceleration it smooths out and runs fine. Can anyone help me out as I and my mechanic cannot seem to find the issue.

 

Find a new mechanic. Sounds like he's been shooting the parts cannon at it. What brand injectors? Sensor? Cap/rotor? Plugs? How's the throttle body? Have you cleaned the IAC? Did you replace the O2 sensors? Mix up any wires?

Any of these can cause performance issues.

 

What brand crank sensor? (duralast?) These trucks REALLY don't care for aftermarket sensors in critical locations.

 

We are not shooting the parts cannon as of yet I had all these parts replaced when the Crank Position sensor went out, What has us puzzled is the truck runs beautiful till it gets warm then the misfires start of I could keep it below 100 degrees it

 

I do believe it is a Duralast what has us puzzled and i should have mentioned this before when the engine is cold it runs fine it only misfires when its hot and at idle over 1000rpm and its fine

 

also over 1000 rpm and she is fine it only misfires at idle

 

Disconnect the front O2 sensor, go for a drive. Problem gone? Replace the O2 sensor. (NTK or Denso please, stay away from bosch.)

 

Will give it a try , Thanks for the info HeyYou

 

HeyYou I think you found the issue I have the upstream 02 sensor unplugged now the only code I am getting is the 02 sensor open code not P0300 thru 308 misfire codes ,

 

If it is running better now as well, put in a new sensor.