Vehicle is a 1996 Ford Explorer, 6cyl, 90,200 miles. Autozone got a code of P0401, insufficient flow of EGR is detected. Any advise on how to correct this is much appreciated.

 

Replace the EGR valve. They are cheap and need to be replace often. If that doesn't do it you got me.

 

dont replace the egr they hardly ever fail on fords you either have a restricted passage in the intake or a bad dpfe sensor.

 

You might aslo check the vacuum lines from the manifold to the vacuum solenoid and from there to the EGR valve. They sometimes go bad and leak and will rpevent the valve from opening properly. Not sure if the P0401 is the code that would be set for a bad vacuum line, but it's an easy check/fix if it's the problem.

Some more info:

http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0e/2f/4e/0900823d800e2f4e.jsp

 

Check the hose to the EGR. If there's a leak there, the lack of pressure differential can certainly post that code. EGR valves don't plug up the way they used to, so I'd look at the hose first. Just had to replace mine on a '97 Villager.

 

This is another "way too many things that could cause it" code. The most likely cause is a bad DPFE sensor. The only way to know for sure is to test the system. If you don't have the proper tools a vacuum gun would help the most. First inspect the hoses going to the egr valve and dpfe sensor, also wires to the dpfe. Then start the vehicle, disconnect the vacuum hose at the egr valve and hook up the vacuum gun. apply 5 - 10 in of vacuum, if the engine runs very rough or shuts of, the valve is ok and the ports are not clogged. If it doesn't, you have a bad valve or clogged ports. Otherwise it is MOST LIKELY the dpfe sensor. Again without proper testing you can't be 100% sure.

 

I agree with TOPTECH. It's most likely the DPFE sensor. They have been a problem on fords for years.

 

Twas the vacuum switch.

 

Chalk one up for the tow guy.