I have a 2003 F-150 V-8 4.6L
When stopped or in idle the engine shuts off. The truck will restart and run fine. Service engine soon light came on...PO171 code. Changed the MAF sensor and air filter. The truck is still doing the same thing as before. Manual says to check the EGR valve..anyone have any other ideas?

 

I don't have my manual on me, but I thought code P0171 was lean bank 1. When I've seen that code, it's usually a vacuum leak or fuel filter.

For the MAF, you'll usually get code P0101 and would be suffering from very poor gas mileage. The EGR valve seldom causes stalls, and you'd probably be getting a code in the neighborhood of P0401. The next item in line after the MAF is the idle air control. A sticky IAC will definitely cause stalls.

 

I have a 2001 F-150 Supercrew V8 4.6L and I have been having the same problem. When I am stopped it acts like it's going to quit but I put it in neutral and rev it and it starts running fine. It doesn't do it all the time. My check engine light has not came on though. I have changed my spark plugs, plug wires, changed my oil, changed my pcv valve, and changed my fuel filter.

 

Here's the thread on that code. Yep lean bank 1.


https://www.f150online.com/forums/sh...d.php?t=239256