01 Ram 1500 5.9 1500 P0171

[retnavy]

Recently, my Ram showed a P0171??? New cap, rotor, wires and plugs. Runs good until ya load up the engine. Feels like starving for fuel. Did have miss fire codes prior to new wires plugs etc... Engine idles smooth, like you wouldn't know anything wrong??? Only with engine under load. Can't find any vac leaks. Any ideas???

[The Fast Forester]

I've got an '01 1500 with the 5.9 that exhibited similar symptoms, except I didn't have a check engine light on. Kept getting worse to where I barely had any power driving down the road. Checked the fuel delivery system, it was fine. Pounded on the cat convertor and heard some loose parts in there, took it apart and it was wasted. I'd recommend looking at your exhaust, especially the catalytic convertor.

[angus10]

Could be O2 sensor(s) also. And you should check fuel pressure and flow. But with the way these things eat converters I agree that you need to check it.

[retnavy]

Check fuel pressure, had 46-48 psi in gear and a/c running. No O2 sensor codes. Problem is intermittent and seems to happen after driving for a while mostly highway. Hasn't given me a problem today, had a convertor problem on my last 94 Ram.????

[angus10]

You should check the converter then. Sometimes after they heat up and expand, things can move around inside.

[elite1msmith]

any fix on this?