orihara1

I have a 2005 Ford F-150 with a 4.2L V6 engine and 135,000 miles. It was throwing a P0191 code so I replaced the fuel pressure sensor, fuel pump driver module, installed a new battery and verified that the fuel pump fuse was not blown.

The truck started with difficulty but lacked power when accelerating. So I cleaned the MAF sensor and installed a new air filter. However, now the truck starts but immediately stalls out. While the check engine light is no longer on, the dashboard displays a "check gauges" warning. I'm uncertain about the next steps to take.

Thank you!

Jimboy

SOMETIMES when the trucks starts and dies immediately there is an exhaust restriction, possibly a clogged catalytic converter.
Is your running fuel pressure steady (after initial pump up) at approximately 40 psi as measured by your computers Point ID or about 30 psi as measure by a pressure guage

orihara1

Thanks for the response. I'm attaching some readings from my scan tool with the truck in "ignition on" mode. (Hopefully the images are the right size!)

Jimboy

Your igition ON information in regards to fuel pressure 63.501 is above 40 psi (nominal running pressure) and is also above the computers Desired Pressure of 55.222 psi at these conditions. These numbers indicated that the fuel pump is capable of meeting the pressure requirements and is ok. I realize you are having problems keeping the engine running but we need the pressure info when the truck dies even if that is seconds after the start.
I am going to guess the pressure is going to stay above ~40 psi during the stalling event and that fuel pressure is not the problem.

Restricted air flow is my guess as to where the problem lies. Check and make sure your air box intake is not clogged. As a check you can disconnected the air intake hose from the throttle body and see if the truck will start and run (this is for testing only)

There are a couple of ways to detect a clogged exhaust system. Do not run for more than a couple of minutes with these disconnected or you risk a fire
1) You can loosen the bolts holding the exhaust system to the exhaust header enough so that exhaust gasses can escape through the gap. Use plenty of PB Nut Blaster on the threads before trying to loosen those nuts.
2) You can remove the upstream oxygen sensors so that exhaust gasses can escape through the hole (s).

In my experience catalytic converter failure is often the problem when you have a situation where the engine starts and dies immediately especially if it was preceeded by diminishing engine power.

Give us an update as to where we stand on this issue.