1997 FORD F150 P0401 EGR Flow code with 5.9L engine

Question:

As per your ATS instruction manual, I changed the egr valve, dpfe sensor, egr solenoid including the blowing of air passages of the egr system of this engine yet this same code keeps coming back. Am I missing something? I also reset the code but the check engine light with the same code is on all the time.

ATS Adviser:

Although you replaced all those parts, you did not indicate if those parts are from Ford which makes a lot of difference. Sometimes when you use 'aftermarket" parts, the quality might not be comparable. Also, when you said you blew the passages of the egr system with air, did you remove the throttle body? The carbon build up inside the intake manifold ports is very difficult to remove unless you take out the throttle body.

ATS Tip:

When the same code appears, it shows the problem is not solved like restricted flow.