Does a catalytic converter cause the car to overheat?

It can cause this problem since you will have to work the engine much harder to get the power needed and the exhaust can not get out. If you are talking about water temperature being too high, not really. Check for a sticking thermostat on this one. More often it will cause a loss of power and if it has a carbarator it can cause spit back out of the air cleaner.