Alero misfiring after overheating

2000 Alero with 3400L -107000 miles. Daughter driving an car overheated. Dont know how long she drove it until she shut off. I refilled overflow (low on water) now engine misfiring an service engine light on. Idling an service engine light blinks but stays on constant if you are driving it. Took to Autozone an code read PO301, # 1 cylinder misfire. Changed plugs but didnt fix problem. Also now red box light on dash over temp gauge on. Any suggestions? :rolleyes:

How about the ignition wire or swapping the coil packs around? Hopefully she didn't blow the lower intake manifold or headgaskets. Pull the #1 spark plug and see what it looks like.

When I originally changed out the plugs, you could tell that they looked like they had gotten real hot. Dont know why it would have gotten low on water. Had to add about a 1/2 gallon today after letting it run for a bit checking over things. Still losing water. Does it sound like maybe a blown head gasket an thats why it was low on water in the first place?

"Red box" on dash is the low-coolant warning, from the float-sensor in the bottom of the coolant reservoir. Do you know if the LIM gasket has ever been replaced? Search for "LIM gasket" on this forum, these engines are famous for needing them replaced, one symptom is constant need to add coolant.... other symptoms are either oil in coolant, or coolant in oil.