low rpms/dies at idle when warm

I have a 1993 G20. My problem is when the engine is warm it idles rough at ~300 rpm or dies when coming to a stop. I took it in to a shop and they told me the O2 sensor was bad and the fuel injectors needed cleaning. I replaced the O2 sensor, this did not help. I have run a tank of high octane (93) with fuel injector cleaner through with no help. Any ideas / suggestions?

Cleaned throttle body with throttle body cleaner and toothbrush - no help.
Cleaned PAIR valve - no help
Adjusting Throttle screw has almost no effect on idle.

I have the same problem with my 98 ford escort. The Ford dealer told me, and replaced the airflow sensor, AND the O2 sensor, after telling me it was fixed the first time by just cleaning the air flow sensor. So with a cost of about 500 bucks, its still not fixed. If you find out anything please let me know. I'm taking it to a shop today, not a ford dealership and see what they say. Its funny though, when the car is acting like this, my car alarm doesn't work, when the car is running fine, the alarm won't arm/disarm.......strange

i am having the same exact problem with my g20, iwas able to adjust the idle to a point where it doesnt stall but it idles at about 1300-1400, which isnt exactly ideal

got that prob with my p11. Changed the air flow sensor, and adjusted the trottle body and it works fine now.
My sped sensor is bad . It causes the car to pull off at exreemly low speed and very high rpm. HELP!