I have a 2002 ram 1500 with the 5.9 magnum 203k on the motor, and lately I’ve been having a hard time with it wanting to Stay at a normal 600 rpm idle, every once in awhile. I thought I fixed the problem a couple months ago but it’s back.

Ive put new O2 sensors, plugs, wires, cap, rotor, fuel pump and all the sensors in the throttle body within the last year or so, so I know it’s none of that.

Every once in awhile it throws a code saying left bank is running lean, but it blows black smoke, I found a vacuum leak and fixed it and have also ran some injector cleaner through. I’m not sure what else it could be but everything leads to a problem with how much fuel it’s getting.

It will usually happen when I have over 3/4 of a tank of gas and only happens with no load on the motor and when it’s in gear (most of the time)

Anyone have any idea on what it could be?

 

What brand O2 sensors?

Maybe a sticking injector.....

 

Yes the 02 sensor brand makes a difference with a lot of the dodge engines ,NGK/NTK sensors are best in the 5.7 , unsure about the 5.9 but Bosch sensors doesn't play well in moper generally ,,even then if you use the NGK/NTK and have problems and that code its either a bad sensor or perhaps a wiring issue to the sensor or as stated above the injectors could be sticking

 

Just a guess and I cant remember the configuration of the 5.9. sticky egr ?

 

I was thinkin' about that too, but, 02 shouldn't have EGR.