Car has no power and can't rev above 3,000 RPM..?

My first thought is timingh chain skipped a tooth or two.. but i wanted to get some other opinions or things to check first... I'ts a 2001 Olds Alero, 2.4 quad cyl. 5 spd. manual. Engine was running PERFECT, then drove it 50 miles, and now this.. No power, can hardly get up even small hills.. Idles perfect though. stalls out and sputters at 2500-300rpm, even with the pedal to the floor.