bjlovejr

Ok so I changed out my EGR valve because the other was stuck closed. I ran a quick scan with my OBD2 meter and the first code I got was say it was DPFE. So I replaced it with one from Summit. I also replaced the actuator solenoid. Now I’m getting code P0401 (insufficient flow). Truck sounds and feels like it wants to die at a red light or stop sign. Acceleration is lagging and hesitant. No check engine light. Changed plugs. Alternator and battery was changed about 6 months ago. I’m running out of ideas and money. I need any other ideas of what I’m missing.
Info: 2001 F150 XL 4.6 2WD supercrew

Jbrew

The 401 has nothing to do with the way it's running. However, cleaning the plugged ports in throttle body elbow would get rid of the code. Yea, that is solely a 4six problem, they're are good for that...it's a common problem.

As for the way it's running. What type of plugs did you use ? Have you noticed a blinking CEL at anytime in the past? Like say , blinking 2 or 4 times at random, out of blue then it stops

Also, disconnect the green line from the EGR valve. Give the valve a couple taps with the end of a fairly large screw driver. See if that changes the way it runs, take it for a drive with the green line disconnected. Any change?

BTW- here's a diag of the EGR system parts, - so you know what's what...just in case, -

http://www.fordscorpio.co.uk/egrmonitor.htm

bjlovejr

No i have not tapped the new EGR valve. I also have not ran it with the green vacuum line off but will give them both a try. Never had the CEL light flash at me. Not that I have ever seen anyway. Replaced the throttle body about a year ago. Did a full cleaning with a cleaner I got from Oreilly auto and did a complete port scrub. I’ll give you an update after I pull the vacuum line and tap the EGR and run it for a little while.

River1

Where are you located? Yes, with the EGR valve this can matter. Have you done "ANYTHING" to change your exhaust system? What DPFE did you get from Summit? Does this happen when the engine is hot, cold, both? You identify it happens at low rpm's, what about high rpm's? How did you determine your EGR valve was stuck closed? How did you determine it wasn't closed because of the DPFE? Do you have a stock tune?

Have you tried disconnecting the MAF to see what effect that has on your problem?

bjlovejr

it’s all stock beside the cold air intake. And btw, didn’t mean to put closed. It was stuck “open”. A friend of mine has AllData and threw a code that I was running lean. We couldn’t find a vacuum leak and determined it was the EGR valve. And I can’t remember the part number from summit. But it is an identical piece. Ran with the green vacuum line off for a little bit after giving the EGR a cpl of taps and it seems to run a little better. But still has a little shaking when accelerating. I put the vacuum line back on and we are back to hesitation and crappy acceleration. Location: Mississippi
also did a plug change about 6 months ago. Tuning delco’s. I have also changed the PCV valve in the past 3 months

JCR 56

Always use Motorcraft plugs.

bjlovejr

Wow. Thanks for the input