When the car is in park or neutral it will idle and the engine will rev properly. In reverse, drive, 2, and L, the rpm drops below 1k and hitting the gas wont get it to rev properly anymore. the car has been sitting for a couple weeks. I just changed the oil, oil filter, air filter, knock sensor, radiator, and added transmission fluid.
The car recently overheated and the cylinder head had to be re-manufactured.