Last week my 5.4L Triton puked out another spark plug. I was hunting when it happened and my truck was at the end of a long frozen road that was about to thaw into a long muddy road. This is about 70 miles away from my home. So I get the truck towed to the nearest town and a shop there fixes it. I go pick up the truck the next weekend and as soon as I start it the "check engine" light is on. No biggie I figure...they forgot to reset it.

When I get home (70 miles later) i have autozone check the code for me...it says P0401 EGR flow problem. Long story short I buy a DPFE sensor and replace it. I heard that is usually the culprit. I change it out, reset the light and I'm good to go. 7 miles later it's back on. A return to autozone shows the code is again P0401. WTF? I figure it must be the EGR valve itself...so I buy one and replace it. Light goes out...5.8 miles later the light comes back on. I go back to autozone and guess what? P0401. Now I'm pissed off and I get to doing some research...research I should have done more of on the front end but I was in a hurry and tried to take a short cut.

Now I read that sometimes the ports in the throttle body get fouled and block flow. So I take the throttle body off this morning, clean the hell out of it and reinstall. When I'm done with that I see that two hoses aren't connected. I never unconnected them so I'm a bit surprised by my find.

When I extend the hoses to see if there is any natural place that they might line up....they go right to the two downspouts on the DPFE sensor. Ho-lee-****. The shop that did the work on the plug removed these lines when they did their work but never put them back...which caused me to get and EGR code P0401. I had never worked on a DPFE sensor...and there were no hoses connected to it when I removed it so I had no idea there were ever supposed to be any hoses connected.

I spent 130 bucks on parts and about 3 hours of time trying to fix a problem that wasn't there...the mechanics just did a poor job of reassembling my truck. I would have just brought the truck back to them immediately if they were in town but getting my truck to a shop 70 miles away is a logistical problem...especially since they aren't open on the weekends.

What a pain in the ****. Truck runs great though...and it was fun to remove the throttle body and clean it...learned a thing or two more about my truck.

I thought I'd never get that dang light to go out.

 

Well hey, just chalk it up to experience, and you got a lil preventative maintenance in at the same time.

 

I hope you kept the old dpfe. That duralast may last, and it may not. Glad everything worked out for you in the end.

 

hard to believe you never saw them disconnected when you went to install the dpfe see an how they connect to it and all..

 

This. At least your TB is clean now. It probably needed it anyway.

 

i dont mean to hi-jack your thread, but i have the same code, minus the fouled plug. i have been driving it a while with the ses light on with no problems. this being said, do i need to replace the DPFE sensor. i really dont know since its my first f150...newbie here