I have a 2000 Honda Accord that was hit by a deer. Sat in a garage for 4 years. I fixed all the cosmetic issues, replaced radiator. Ran fuel and treatment through, changed oil ect. My check engine light flashes and in idle it revs up and down consistently. I’ve tried cleaning the valves on the throttle body but haven’t changed any sensors as I don’t wanna just throw money at it. Checked codes and it says misfire in cylinder 3 and map sensor. Can these be the cause of the idle issue?

 

Have you checked spark ? put a tester on it to see. If yoou want to diagnose it to make sure it seems real, swap cycl 1 wires and spark plug with 3 to see if it moves. If it does, just swap in new plug and wire. I don't think these cars like to sit too long, the electronics get cranky.