Dies when engine warms up, won't restart until it cools. Ideas?

2000 Nissan Quest won't run. Months ago engine light would come on for a day or two then go off. Then I began to notice a little jerk every now and then, husband didn't even notice it. It of course got worse with time until it was very noticeable. Jerking and sputtering like crazy. It would idle so rough it would die. Husband would keep one foot on gas and one on brake and keep it reved up or it would die. Our mechanic found knock sensor code. He has replaced lower and upper intake gaskets, spark plugs, wires, cap and rotor plus some other stuff I can't remember. He said it idles well now until it gets warm then it starts bogging down and dies and will not restart until it has completely cooled. He replaced thermostat because it had been acting weird. He is thinking of replacing distributor next. We used to have a plymouth which would only drive on short trips less than 10 miles or it would die until it cooled, we replaced crankshaft sensor on it and it solved its problem. What do u think