There could be many things that are causing the problem. Have the computer scanned to identify where the problem may be coming from. Have it scanned when the light is on.

Restricted performance usually indicates problems with the air intake/throttle body or the fuel system. Start by checking the obvious things like the air intake box (air filter housing) for cracks or to make sure all of the clasps are fastened/not missing. Check the breather hose from the engine that intersects the intake pipe to make sure it isn't cracked and that both ends are completely fastened. If there are no problems check the mass airflow sensor right after the air intake box to make sure the wiring harness is completely fastened and remove it and apply a small amount of cleaner if dirty. If this checks out check the air intake pipe for cracks and where it connects with the throttle body and make sure that seal is tight. If this fails to fix the problem you need to check the o-ring seals around the dipstick and the breather hoses between the engine and the firewall and the plastic air intake manifold seals. If all of this is unsuccessful you may have a clog in the fuel lines or a fuel pump problem, but the latter would likely mean it would not start. Usually this is the air intake. Mine had a faulty dipstick o-ring, faulty mass airflow sensor and a cracked breather hose, and the plastic nozzle that extends from the valve cover cracked. Also when I bought it a mechanic had been too rough with the air intake box and cracked a large piece and a clasp off. These all happened at different times. Not too expensive to fix, especially yourself but annoying.

Of course check the codes (you can borrow a code reader from autozone, o'reilly, etc.) This will let you know where to start looking.