I have a 2001 Ram 1500 4wd with a 5.9L. Lately when I start it every thing is fine for several minutes and then it seems like it is loading up on fuel and misfiring pretty bad. I sit there and play with the throttle and eventually it stops misfiring and then it is good for the rest of the day. After sitting overnight and cooling completely down it will go through the same thing the next time I start the truck. Anyone have any ideas?

 

Have you had the PCM scanned (via OBD2 scanner) to determine if there are any pending or stored codes that may help to narrow down the issue? Is the check engine light on? Is the truck's battery very old?

 

I had the PCM scanned and the only code showing up had to do with the brakes which I knew a while ago. The check engine light is on. The battery is only 1 year old.

 

Any oil down in the intake plenum? Has the plenum gasket been changed on the intake manifold? See this thread for this common problem - https://dodgeforum.com/forum/2nd-gen...um-thread.html

 

Thanks I will check that oil stuff out tomorrow and read the thread you left a link for.

 

Disconnect the front O2 sensor(s), see if the problem goes away.

 

I recall reading a while back that these Dodges use a certain plug and if you try to use a cheaper plug they won't last to long. What is the recommended for the 5.9L?

 

Are both upstream sensors tied together or do they have separate plugins? I see 2 sensors just ahead of the converter. the wires run up over the tranny and I don't see 2 connections. One sensor has a visible connector but I don't see another connector unless I need to dig deeper. Thanks to everyone for all your help so far. It gives me something to go on.

 

Just the opposite, you want to use the regular copper plugs. They don't like the rare-earth fellers, and they have been know to cause issues. (mystery misfires, and such.)

Should have separate plugins. Likely up above the trans somewhere...... Yeah, that was good planning, wasn't it....

 

Well I can get to the plug by putting my arms around the trans on both sides. I can feel the plug. I assume I just squeeze the tab on one side and pull apart?