Hi. I have a 1996 Coachman RV which sits on the E350 chassis and 460 engine. Once the engine warms up, and the accelerator is depressed, the engine will start to miss, sputter and die. If I turn it off and start it immediately, it will run great for about 2 miles then do it again. I can actually shift it into neutral at highway speeds, turn it off, start it, shift it into drive and continue.

Here are the codes:
172 EGO Not Switching, Lean exhaust - bank 1

334 EGR (EVP) Voltage above closed limit

542 Fuel pump circuit open - ECA to ground

I have replaced the fuel pump and one of the O2 Sensors so far.
any help will be greatly appreciated!

 

Since code will stay stored even if an issue is resolved, I would clear the codes since there is no way to tell if they were pre-existing before the trouble started. Also, when was the fuel filter replaced last? If not for a while, I would replace it, clear the codes and start with a fresh slate.