P0401 (EGR Flow Insufficient)

[SpeedNinja]

I've been chasing several issues on this truck for a while now. (Bank 1 Lean started it, replaced a lot doing that.) The most recent are the P0401 (EGR Flow Insufficient) code and the truck having a high engine speed between gears or after giving it gas while sitting static.

We just replaced the DPFE and the code came back after a couple days. Can't find any other leaks in the EGR system. Could the valve itself cause this code?

I'm not sure what the high ending speed between gears is from, other than the ECU not being able to correct for something else. The only parts I haven't replaced are the intake temperature sensor and the TPS.

 

[adsm08]

Valve or vac line to the valve. Get a hand operated vac pump and apply vacuum to the valve with the engine idling. You should be able to stall the engine.

A leak on the engine side of the egr control lines could account for both the p0104 and the high idle.

Postin' from teh Galaxy

 

[SpeedNinja]

I'll have to get a pump then. Any ones in particular that are good, or that should be avoided?

When you say "a leak on the engine side of the egr control lines", where exactly do you mean?

 

[Buhz]

vacuum leak possibly

 

[adsm08]

There are two vacuum lines and one vacuum control solenoid that are used for controlling the EGR valve. There is a red line that runs between the intake manifold and the control solenoid and a green line from the solenoid to the EGR valve.

If that red line is broken and leaking it can cause your low EGR flow codes and screw with the idle/return because the engine is sucking air through that damaged line.

The easy test of the line is to pull it off at both ends, put your finger on one end and blow in the other, if it holds pressure it is OK.

 

[Mazda]

Check out this site I found a while back. Really helped me figure out why I was getting that code.

http://easyautodiagnostics.com/ford_egr_test/ford_egr_valve_1.php

Also I have theOEM brand pump that Pep Boys sells . Worked good but is all plastic. Took it back a got the Craftsman one from Sears ythat is all or mostly metal.

Bryan

 

[adsm08]

Also I have theOEM brand pump that Pep Boys sells . Worked good but is all plastic. Took it back a got the Craftsman one from Sears ythat is all or mostly metal.

I have had both of those, and believe it or not I think the plastic one is better quality.

Thing is, you aren't supposed to suck fluid up into those pumps. The craftsman one stopped working after the first time it got a little fluid in it.

My MightyVac (same as the OEM, just a different name on it) has sucked up trans fluid, brake fluid, oil, coolant, and the most it has ever needed to get back to going is to take the front piece off and rinse the seals in some clean water.

I do like that after the craftsman one quit working I was able to pop the gauge off, stick a line on it, and then I had a nice vacuum gauge.

 

[SpeedNinja]

The weird idle issue went away. Mom has been driving the truck the past two weeks. Dad cleared the code for her and it hasn't come back within the range of time it normally does.
I had bought a new EGR valve but never installed it, which looks like I can get my money back on.
I'll check those plastic lines when I get a chance.