car was running fine then all the sudden lost power and started running rough. took it home changed plugs/wires cap rotor and coil still having same problem. fuel injectors have benn a little louder than I would expect them to be could this be my problem??  

Did you use premium Gas. Might have been bad gas. Fuel filter. Injectors are a little loud but if your talking loud loud, then maybe. You can try some Chevron Techron fuel system cleaner. Also some gas stabalizer to remove any water that mightve gotten in there along with a new fuel filter. Also check any codes if your check engine light is coming on. Goodluck.  

Could also be the timing gear, Check your new plugs for any fouling.  

Sounds like the Mass Air Flow sensor went bad. Are you getting a check engine light? Even if you aren't that's where I'd start.

The timing chain could possible be the problem also. How much time is on the chain? Is the car making black smoke out of the tailpipe?