Lingering Problem

[2wistd]

This has been driving me crazy, but my check engine light has been on in my car for what seems as forever. I've had several shops look at the car including a dealership in OH. Now the car is in CA and it needs to pass smog. It won't because of the CEL.

The code that it gets it for the IACV or Idle Air Control Valve.

The things that have been replaced in the car:
Cat
IACV
O2 Sensor
Intake Manifold Gasket
Coolant Sensor

I've checked the hose between the MAF and Throttle Body and it has no leaks. The MAF looks clean on the inside.
I've tried to have the car relearn the Idle Air Control. no luck. Can I calibrate the MAF?

I'm in Norcal, close to SAC. I am curious if swapping parts with a working car could help diagnose, but I don't know anyone with an 2001 or similar Altima
Any ideas? Help?