I have an automatic 2002 Sunfire 2.2. About 1.5 months ago i had to replace my timing chain, head gasket, 2 valves - the works. Now... suddenly my car has a problem with shifting. Before my car would shift around 2500 RPM, now it takes between 3000 - 4000 RPM. I almost have to remove my foot from the gas pedal like i'm driving a standard. Sometimes my car also has a problem gaining speed. When I step on the gas - it dosen't accelerate at all, my speed just creeps up, while my engine runs at high RPM The engine light has been on for a while, since before my timming chain, and this morning, the TC light (the one with the slash through it) came on and wont come off. I have had people tell me its sucking air somewhere.

Also I noticed this morning, when my car is in park and I step on the gas, there is a rattleing coming from under the engine.

sounds like a vacuum leak. also go to autozone or a parts place to read your codes. they do for free.