Just repaired a stripped spark plug hole (#4) on a 2000 Protege. Removed the wires and ended up crossing them up. After the repair and assembly the engine shook like crazy and was misfiring on 2 cylinders. Had an engine diag done, have it wired up now as 2-3-1-4 and runs smooth as could be. I believe 1 and 4 are "constant" but 2 and 3 can be interchanged. Hope it helps.