Ok last week my XJ ran real smooth for 2 days didnt miss at all, then all of a sudden it has a rough idle again. Its almost like if I drive it normal for a few days it smooths out, then if I get on it or take it offroad or something like that is when it starts acting up again. So far I have replaced plug/wires, cap/rotor, cleaned pcv, cleaned throttle body, seafoam in brake booster vac/gas tank, removed catalytic converter. :banghead: