Anyone know if this means my EGR valve is bad? Its a 96 F150 with a 302.

P0401 Exhaust Gas Recirculation Flow Insufficient Detected

The EGR tube was replaced with a new Ford tube a few years ago and I have replaced the DPFE last year but with a used one from another truck.

 

The DPFE sensor is what measures airflow through the EGR tube, so check that the small lines between the DPFE and the EGR tube are intact, and then check that the EGR valve itself is operational(apply full manifold vacuum directly to it to make it open). When you do this the engine should stumble, but if it doesn't then the port between the valve and intake may be clogged with carbon.

 

Do the test conanski recommends and if the engine stumbles or dies then the valve is good. If so then you should check the vacuum line between the valve and the solenoid on the other side of the intake. I had the same P0401 and found that the vacuum reservoir had a quarter coin size hole in the underside. So much for thinking I was immune to that with the plastic one. If the line and reservoir check out then I would also test the solenoid. I can't remember if it's supply or ground controlled but I'll check in the morning if nobody else chimes in.

IIRC, fordfuelinjection.com has test procedures for the DPFE.