2001 Galant - 2nd Cylinder Misfire

I have a 2001 Galant with about 87,500 miles on it. When I bought it (2001), it was a 'demo' car and had about 12,500 miles.

It had given me little trouble until this past year. I had the rocker-arm replaced on the passenger side.

Summer of 2010, I had to have the radiator replaced. It didn't have a history of overheating (that I could tell) but one weekend, it suddenly overheated and the a/c shot off etc. I pulled over, let it cool and took it home. Had it replaced a couple days later.

Fall of 2010, it started sputtering when the engine was cold, especially when taking off from a complete stop. I took it back to the same people who replaced the head gasket, timing belt and water pump. I think they said oil was seeping somewhere causing it to misfire. (I think they changed the spark plugs etc at that time.)

A month or so later, the oil light flashed on then off. I checked the oil and had to add about a quart.

It's doing the same thing again now. Sputtering when taking off from a stop etc. Especially when cold and the engine light is on again.

I don't want to be pouring good money in after bad so I spent $20 and got a code reader. There are two fault codes, P0401 and P0302.

Do you have any suggestions? I would love to keep the car (I hate the idea of having another note) but I've already put close to $2500 into it this year.