I recently bought a 2003 4.7 ram. It runs rough, no ticking or knocking sounds coming from the engine. I hooked up the code reader and got P0172. What is the connector that sits on the passenger side fuel rail? It's toward the back of the engine before the 4th plug on that side. I'll try to get a picture. Anyone have the same problem?

 

Correct the code, that should help your issue.

 

Turns out one of the oxygen sensors had a melted connector and was making contact with the pipe. Fixed it, but now has P0121, Throttle Position Sensor. Bought another, installed it and is still doing the same thing. It has difficulty starting, and idles rough, and smells rich.

 

The truck is still doing the same thing. Trouble starting up, rough idle, exhaust smells very rich, no ticking or knocking.

Idk if this truck has had an engine swap. It has a 4.7 but don't know if it's the original. The engine has an egr valve, but there is no plug for it. Did non-egr trucks come with egr engines? Pardon my ignorance.

 

What leads you to believe the engine would have been swapped?

 

The engine has an egr, but there is no plug for it.

 

They don't come with valves unles they need them, could be a boneyard engine, means nothing really as long as it runs good. If you changed the TPS but still have a code you'll need to check the wiring going to the PCM for continuity and to see if it carries a load, if it's all good you likely have a PCM problem.

 

I would search around for the plug. Someone may have cut the connector off of it. If it has a valve, it would have been plugged in at one point. My guess someone unplugged it due to a code.

 

Thanks for the info fellas.

I suspect it is the pcm too. I found one of the oxygen sensor wiring completely melted on the exhaust. Not sure if that could have fried the pcm. But i'll inspect it a little closer tomorrow.