1997 Jeep Grand Cherokee, V6 in Chicago, IL

1997 Jeep Grand Cherokee, V6, 188,000 miles. Needs coolant sensor. Drives fine but has rough idling at times which causes a few minutes of a jerky ride - but eventually smothes out. Research has shown that jeeps of the same year have this problem. I've replaced the crank sensor, oxygen sensors , distributor cap, and rotor with no effect on solving this mystery. Online research showed that those that have changed the computer, which can be bought on line for around 250.00, has solved the problem. Using premium gas has a positive effect on the engine running less problematically.