1998 Ford Expedition P0401, P0402, P1401 Engine Code/ A vaccum line could be your problem/ Eps. #89

In todays video I continue to chase that pesky P0401, P0402 and P01401 engine code!

There is a lot to cover in this video and a few updates after I shot this video.
I AM NOT A PROFESSIONAL MECHANIC AND I AM ONLY TELLING YOU WHAT I HAVE DONE SO FAR TO FIX THIS PROBLEM.

When I bought this truck about a year ago it had around 138,000 and to
day it has 151,000 on the odometer. This truck was a law enforcement truck driven by a detective, NOT a patrol vehicle. The truck was serviced pretty regular but these trucks do have their common issues. I don't really know why the police department sent it off to but i can image it had something to due to its age. I bought this truck from an individual the bought it from the auction. He stated that he had the intake gaskets replaced and a tune-up preformed. The truck ran good and had no check engine lights at the time I purchased it.

Let's talk about the first time the check engine light came on pertaining to the P1401 engine code. This is a DPFE (Differential Pressure Feedback Sensor). This sensor is located on the drives side of the engine up near the EGR valve. I stopped in to a local Autozone store to have them read the code and was told this sensor would fix the issue. Now this truck still had the original DPFE sensor so it needed to be changed away. THIS DID NOT FIX THE PROBLEM.

This became intermittent and seemed to really act up when conditions were wet outside. The engine would miss fire and the engine would stumble all over its self. Now with that being said the check engine light would come on and then flash to indicate a misfire. When I would scan the engine codes it would show up as P0401 and P0402. This was very puzzling for me so I started watching every video I could watch on this topic.

The right thing to do is not what I did which was throw parts at it. I put a new EGR valve and removed the throttle body spacer and cleaned the heck out of it. Well that dang code came back intermittently, again!

I am getting a little irritated with this truck to the point of almost just buying a new truck and that leads me to want is in this video.

Please watch this video to see what I did.

UPDATE:
After filming this video I drove the truck about 120 miles in the snow and guess what came back? That P1401 engine code! When I got to my destination I popped the hood and noticed that I forgot to plug up my DPFE sensor. LOL.

Since then I have driven about 600 miles with no more check engine lights.

Thanks for watching!

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