2.0L Dodge Neon 2003 P0303 but the check engine light does not stay on it just flashes almost every other day?

run a compression check on it to see how much it has on each cylinder ,first do a dry test, then squirt a small amount of oil in the cylinder and do a wet test and see if there's a big difference,if there is you may just have a bad valve in the head,i ran across one the other day with a miss fire and it only had about 60 thousand miles on it,also you cant remove the code by removing the battery cable on that one,you have to do it with a scanner ,that would work on the early models but not with obd-2 system on it,the code will keep coming back even after the problem is repaired,good luck with it.