rough idle after cleaning throttle body, IAC, and EGR
I have a 1997 F150 XLT 4.6 4X4 SC. I got the P0401 code, EGR pressure error, so I took off the EGR, IAC and throttle body and cleaned with throttle body cleaner. The ports on the bottom of the throttle body from the EGR were completely plugged with carbon so I cleaned them out so they are now open like they should be. When I was cleaning the IAC, the rod seemed to be sticking somewhat so I used a screwdriver to work it back and forth. I could move it to one side and it would stay put, then I could move it to the other side and it would stay put there. The spring wouldn't retract it, but I don't know if that is how it's supposed to be or not. I put everything back together and it was fine at first, but now 4 days later it is starting to idle rough when it is warmed up and sitting at a stop light, stop sign, etc. Once I take off it is fine with the exception of two or three times it has stuttered under steady speed, like it was starving for gas. Just kind of shuddering. Once I push the pedal down harder, it catches back up and is fine. Does this sound like the EGR is stuck, or is the IAC rod stuck and not moving freely enough, or something else? I hate to start replacing parts not knowing which of them is most likely the culprit. Sorry for the long post, just thought all of this information could help the diagnosis. Thanks ahead of time for any ideas.