2004 Dodge Stratus - No get up & engine light came on?

My 04 Status Coupe (Mitsubishi) recently began to sputter when I step on the gas, only while in gear though. If the car was in park the RPMs went up as they should. This happened for about a day or two and then stopped. It began again yesterday, and then this morning my engine light turned on. What could be the problem - I am at a loss.