1998 Jeep Laredo Running rough

1998 Jeep Grand Cherokee Laredo with a six cylinder engine and 135,000. We were driving home and the Check Engine light came on and the engine started running rough and at reduced power. We made it back ok, but as it was idling the engine cut out. I just replaced the water pump, but don't think that is a related problem. Any advice you could give would be much appreciated!