95 mazda mx6, manual, idles high (175,000 miles)

#1

Since the car was shuddering under load (any gear)I knew a tuneup was overdue. I replaced of plugs wires, fuel filter, air filter, cap and rotor I discovered the pcv valve was not working and the intake was black with oil residue. I knew better than to do this but I used throttle body cleaner while it was running, now the car idles at 2,000 at start up and stays there when it is warm. The IAC has the correct resistance reading but I am curious if it is stuck open? I tried to pinch off the hoses to the IAC to see if the idle would drop but it didn’t seem to affect it.Could the EGR cause this?

#2

I also pulled the electrical connection from the IAC and had the same results. I have checked for vacuum leaks and there are none.