I have recently acquired a 97 f150 4.6 automatic. the check engine light was on when I got the truck. The code is 401, insufficient egr flow. I hahe replaced the EGR valve, solenoid, and EGR sensor but the truck stilll codes. Need suggestions as to what to try next.
Thanks in advance! ::

 

Search this forum, and ye shall receive.

Since you're throwed all the parts you can at it, all that's left is the EGR ports themselves. They frequently stop up with carbonish deposits. You'll need to remove the throttle body elbow and physically clean that stuff out of there.

 

search dpef sensor

 

I agree with Quintin. I believe the EGR ports on the 4.6 are notorious for clogging up.