p1504 idle air control circuit malfunction.

I replaced the Idle Air Control valve with a brand new one. The DC current going to the IAC is 11.7 volts, which is acceptable.

I also replaced the PCV valve (the heated one that goes into the throttle body.) This brought idle down to 1,300 rpm but I believe standing idle in park should be around 750 rpm.

My code reader says the vehicle won't pass emissions so I'm wondering if a bad EGR valve could be causing this?

If current is good to the IAC how could this code remain. I've cleared the code 10 times and taken the battery loose for over 2 hours to reset the computer all which have failed to clear the code.

What may it be? This one surely has me baffled.

Martin