2010 Ford Explorer - P0401 Engine Code - EGR Valve?

2010 Ford Explorer
180k miles

Engine Code: P0401
EGR PTC 89.8%
EGR Error -100.0%
EVAP PTC 60.0%
FLI 66.7%
EVAP_VP -06.54
Short 0.8
Long 0.8

So with the engine code and the above numbers, I think my fuel mixture is okay and the problem is that the EGR value fails to close? I’m curious what others may think because many moons ago I had a P0401 in a 2002 Mustang. I replaced the EGR valvue (myself) and the code remained until I sold the car. I never figured it out. 15+ years, 80 pounds and two back fusions later… I’m too old, broken and fat to be reaching into the engine turning wrenches.

I plan on taking the explorer to the percision auto tune tomorrow after work. They quoted $300 + tax for EGR replacement. However, could it be something else? I guess hoses could be cracked/loose or whatever. I’d like some advice please as I would like to appear mildly “smart” when going to the mechanic tomorrow.

Thank you!

P0401 = EGR Insufficient Flow.

This code can be caused by a dirty EGR valve, or a restriction in the EGR valve supply tube.


No. It might not be closing completely when it should, true enough, but that’s not what the code is for. The code is saying it isn’t opening enough. The EGR is supposed to open when the combustion chamber needs to be cooled off to prevent out of spec emissions. How much it is supposed to open depends on the engine load. More load, like stepping on the gas to accelerate onto the freeway, going uphill, it generally opens more than just rumbling down the street to get a Big Gulp at the 7-11 at 35 mph. The code means the computer thinks the EGR valve should be more opened that it is for the engine load. It determines how open the valve is by some combination of measuring the valve’s temperature, or by measuring the position of the valve’s pintle. The likely possibilities are

  1. The EGR valve is defective and not opening as far as it should
  2. The EGR valve is opening ok but there’s some obstruction in the path elsewhere (carbon deposits)
  3. The valve is opening ok, but the pintle position measuring sensor is faulty
  4. The valve is opening ok, but the temperature measuring sensor is faulty

1,3,4 require the valve be replace probably. 2 requires the valve probably be removed for a look-see. That’s where I’d start, ask the shop to remove the valve. They might find there’s just some carbon deposits that need to be scraped off. I’ve had to do that when my Ford truck’s EGR valve misbehaved.

Thank you for the replies. It doesn’t sound like I will probably end up with a new EGR valve.

I totally forgot to mention - the explorer has a motiveless drop in performance - acceleration wise over 45 mph. And the MPG has dropped from 19 to 16. Some of that MPG drop is more so due to a lack of highway driving lately. However I do feel like this is a moderate issue and something I need to fix instead of ignore.

Thank you everyone.

Well , there is a description that may have never been used before.