i Have a 2003 silhouette 3.4l with 128,000 miles recently it is stalling and throwing a P0101. Once it sets the code it is hard to start. Have to give it gas to get it running. If you clear the code it starts right up and idles fine. I have replaced the MAF and MAP with no change. Inspected all vacuum lines and no problem found. I don't understand why it will start up perfect after clearing the code? I can let it idle for 10 minutes and it will idle perfect. I can drive for about 40-50 miles before it throws the code again. I think it has something to do with the readiness test as it throws the code before it completes the readiness test. Any ideas?

 

jUST AN UPDATE FOUND THAT THE pcm was bad. ECM reference voltage was high on mas air flow and O sensors.