Ford Escape EGR system issues! I would love some advice!

atp2005

Hey fellow Ford owners,

I own a 2002 v6 Escape with 143k miles on it. I recently had a misfire issue so I replaced the plugs and coils. Thanks to Ford making very few things easy to work on, that required me to remove the intake in order to access three of the coils/plugs. After I put it all back together, my check engine light came on, registering a P0401 error code: an EGR issue.Due to the error code, I removed and cleaned my EGR valve, and it appeared to be operating correctly.

The above brings me to my main question: I read online that a way to diagnose the issue is to turn the vehicle on with the EGR valve removed. According to what I read/watched, this should have caused the vehicle to run at very high RPMs, or to not start at all. Well, in my case, the Escape started, but ran at very low RPMs, almost to the point of stalling out. Any suggestions?! I'd prefer not to take this to Firestone for a $100 diagnostic.. : /

Thanks!!

thecardoc3

P0401. That codes means the computer thinks that the flow of EGR gasses when commanded is too low, or insufficient. Ford uses a DPFE (differential pressure feedback EGR) sensor to read the pressure changes in the tube that feeds exhaust gasses to the valve. When you look at the EGR valve and the tube that goes to the rear exhaust manifold you will see two hoses that go to the DPFE sensor. There is a restriction in the egr pipe between the two hoses that creates the pressure differential that the sensor reports. Common problems are failing DPFE sensors, and loss of vacuum supply to command the EGR valve to open. Restrictions of the egr passages also occur but are not as common.

Testing would start with a scan tool that can command the Key On Engine Off self test to see what code is generated, and the Key On Engine On which while also generating a code would allow for direct testing of the EGR valve, the EGR vacuum regulator and its vacuum supply as well as the DPFE sensor output signal voltage as the computer commands the EGR system to operate.