98 sunfire 2.2 187k mi

Car ran awsome as usual all day and suddenly when i pulled into work it was idleing very rough. its only at idle it seems to run like normal as soon as you give it a little throtle. I used search but nearly everyting i seen was 2.4. so far all i have done was pull the plugs and give them a quick visual. I just put new plugs and wires on late this summer as well as put coil packs and ign. module on off a 04 fire. AS soon as it cools down some im going to check spark and look for any possible vac. leaks. I have no CEL and dont know if a scan would tell me anything.

Any help ideas would be awsome. The car usually runs like a top with zero issues and this really bothers and scares me.