I think my car is losing power to 1 cylinder.

This might be an EGR valve. The EGR is responsible an emissions control part located behind the intake in line to the engine. You can take it out and soak it in carb or fuel injector cleaner then scrub the muck out with an old tooth brush. Wear gloves when you do this as the chemicals and the carbon buildup have been known to be carcinogenic. After reassembling, if there is still a loss of power, check your spark plugs and replace them. If that still doesn't work you may need O2 sensors somewhere, or coilovers (which are the wires that connect from the alternator to the spark plugs.) If any of these are bad, then a piston could lose combustion. Also pour two or three bottles of good quality fuel injector cleaner into your gas tank when you are low on gas and run the engine. This will clean out any carbon buildup in the entire fuel system. Autozone will be able to give you the codes though and you can google them, but from all the symptoms, it is my guess that your EGR valve is gunked up. Good luck buddy!