Ok I'm going to explain this the best I know how to. I've got a 2000 eclipse 2.4 auto and it just started this today. Starts and idle's fine but starts to mis when under load. Sometimes it may do it a little at idle also. Sometimes it acts like it wants to clear up but dosent. Service engine light was on and only code was misfire in cylinder #4, cleared it and hasn't came back on. It's almost like a sputter instead of a mis sometimes. Idk if this has explained anything or not. If anybody has any suggestions I would very much appreciate it. Thanks

 

OBD-II Trouble Code: P0304 Cylinder 4 Four Misfire Detected

Best to test/replace your ignition components first.