I have a 97 5.4L with a P0401 check engine code. I have removed the EGR valve and now not sure what to do with it. I just learned there are two types of valves, manifold and ported. I was going to approaching the problem as a manifold type valve i.e. I was going to remove the throttle body and unclog the ports. Now I think it’s a ported valve and I don’t need to clean the throttle body. Can someone confirm this please?

 

Update: I put the valve back on. My research tells me that I am not ready to look at the valve yet but look farther up the system line. More specifically the DPFE sensor. I put a meter on it and got a constant voltage of 5v on the signal wire. This voltage should go from 0v to 5v as the truck warms up but It never did. I haven't measured the voltage with the vacuum lines off. That will be my next test. Also , the vacuum regulator makes a buzzing sound when I shut the truck off. I have read that this in normal and that this is a sign of it going bad.

Any ideas on this? Any help is appreciated. Thanks.