After my head gasket job, I had a DTC of P1507 which the FSM said was the Idle Air Control Solenoid valve. I removed it and cleaned it thoroughly with electrical contact cleaner and I think I've solved the problem. The valve was gummed up with grease/crud from the crankcase gasses. Before I cleaned it it had a slight resistance when turning it manually and aftwerwards there was no resistance at all.

 

It's been a day since I cleaned it. Hopefully the CEL won't come on anymore.

 

Here are some pics:

 

The IAC valve is in the center under the big black PCV hose. It's got the grey three pin connecter connected to it.

 

 

I broke the PCV tee by pulling too hard on the line. It came loose and I broke it. I should have used pliars or a screwdriver to pry it off instead of pulling

 

 

 

Thanks for the pictures. Those old plastic PCV pieces tend to get brittle and crack....no fun.