Its old buy a new car or
replace mass airflow sensor
Hello, the biggest and most frequent cause of the problem you describe would normally be related to faulty, or dirty or plugged fuel injectors. But, if it does not do it all of the time, as you describe, then it may be any of a multitude of other things. And if we can't get it to act up, it is really going to be hard to find and to test for. Because, as you seem to understand, any tests we run on a system that is working ok at the time are going to come back showing everything is fine. On the 2.2L - 4 cylinder motor there were a couple of factory updates for this problem, but that does not help us with this V6 motor. I have already checked with the GM web site and they do not have anything related to it posted as a repair or bulletin. So, I have looked up the most common causes of this kind of a failure and will list them for you below. This is how that are in the eyes of GM and the things they see the most often. Some of them, but not many, you can check for with your eyeball or by looking at and feeling things. The rest of them will require the use of a class 2 scan tool so you can check different sensors to see which ones are operating within normal operating perimeters and which ones are not. Plus, with the scan tool you can do remote function commands to test individual components while testing the system and last but also important, with the scan tool you can set it to snap shot and actually take a picture of the failure as it occurs on the car and then look at the results on the tool. If you can find someplace like Auto Zone or an other large parts store that rents these scanners out, you will be able to spend as much time as you need looking at different parts of the system to find the problem. Other wise you are stuck with finding someone who has the tool and will loan it out or use it for you without charging you a fortune. Good luck with it and thanks.