NCsublime

I've been having this problem for months now. The check engine light will come on intermittently (especially when I don't let the car warm up to normal operating temp-I mean the guage must be as high as it ever gets between hot and cold). Sometimes when it comes on nothing happens, but other times the engine seems to stumble and I have little if any power and the car is essentially not driveable. I pulled the engine codes and got the following:

-(8) Airflow Meter (AFM)
-(9) Water Thermosensor
-(10) Intake Air Thermosensor (AFM)
-(12) Throttle Sensor (full range)
-(18) Throttle Sensor (narrow range)

I can visually examine all of these components (except the water thermosensor which I think is on the water pump), but do not see any visual damage or wiring problems. I have checked resistance on the Airflow meter, and TPS, and they are both within specs. Does anyone have any ideas on what to check and how to go about finding the source(s) of these problems?

Thanks for any help,
Derek