Replaced the EGR and the ruff idle and P401 code came back.

[2006GrayXLT]

Hey guys I replaced the EGR and the p0401 came back on the car after a few days. It also has a ruff idle.. I got the EGR from Advance Auto Parts. Could it be defective? Any other ideas? Thanks for the help.

 

[2006GrayXLT]

Sorry

2006 4.0 4x4 185k

 

[JAWIT]

I had the same problem and bought an EGR from advance. When I swapped it for a Motorcraft part, the code went away.