EGR trouble

Help!!!!I have error code p0401 on my 2001 Lincoln ls. The machanic changed the EGR valve and the solenoid. I drove 20 miles and the check engine light came back and so did code p0401. I'm at mt wits end. The car is not acting up but I cant get my inspection sticker. What could be the problem before I take it back. I read the forum and found out about the clock spring. It was dead on the money. Please help.

It sounds like the exhaust gases + gunk plugged the EGR port, causing insufficient flow to the EGR valve.

The machanic forgot to clean the EGR ports!

The other EGR valve and solenoid is probable good. keep your old parts after service.

I would fire the machanic, if he doesn't clean it for free!

Actually, usually it is the sensor that detects the flow rate that is the problem.

Yep! If there's a block port, it will tell the ECU, and throw a code.

I got a free Lincoln Towncar years ago, because of the same problem!
The customer spent $500 on bad service.

I'd agree that the DPFE is probably the issue. Ford has quite a record of failing DPFEs causing a P0401 diagnostic code. Haven't heard about the failing as often on the LS, but they failed regularly on the Taurus, Rangers, Windstars, and Explorers.

-Rod

Thanks for all the replys. I am off to the mechanic.

Because of Age + mileage, replace DPFE, clean EGR ports, and get a warrenty for service.
With all the new parts + cleaning you will have a new EGR system.