I've noticed here lately that my car at startup will idle weird and sometimes die because the RPM's drop so low. Now it only does the RPM thing until I put it under a load and basically warm the car up. Maybe throttle body is dirty or idle control valve??? The AF ratio reading, I will be cruising and it will range from 10.0 and I have seen it go all the way to 17.2... Any ideas on what this could be? Maybe bad O2 or MAF sensor??? Any help would be awesome.

 

Check the throttlebody, check for vacuum leaks, and as far as AF could be a bad o2 sensor, or maybe an exhaust leak before the sensor.

 

^^What he said.