Engine stalling

Once you restart the engine and start driving again, observe if the stalling occurs when you slow down after not going faster than about twenty to thirty mph. If the stalling only occurs after driving faster than about forty mph, it is likely being caused by a sticking torque converter lockup clutch. GM had a real lot of trouble with them on their front-wheel-drive cars. The common "fix" many people resorted to was to unplug the electrical connector for that feature so the clutch never engaged. If it does not engage, it cannot stick.

The lockup clutch was developed by Chrysler in the mid 1970's to improve fuel mileage. It was hydraulically-controlled to engage above about thirty five mph. GM's version is electronically-controlled and does the same thing. It is the mechanical part that sticks. That causes the engine to stall the same way a manual transmission would stall the engine if the clutch pedal was not pushed when coming to a stop.