The "engine power is reduced" light comes on

You need to get the computer trouble codes scanned
Check engine light on Part Ricks Free Auto Repair Advice

No , reduced engine power message is most often caused by a problem with electronic throttle control , your best bet would be to take your vehicle to a qualified repair shop.

Since all three systems work together, when the engine light is on the other two can be also.
I would start with checking the engine computer for trouble codes.

Did you check for codes & google them,
to see what system has a possible fault

Reduced power is a problem with electronic throttle contol . drive by wire . Do you know what this is ? Taking the vehicle an having it hooked up to diagnostic tool an checking for DTC'S - diagnostic trouble codes is always a first step when trying to find the root cause of any trouble light ! And not auto zone , pep boys , or advance auto parts . Thier diagnostic tool will not check codes in all system control modules .

It is the APP sensors , Your vehicle has electronic throttle control . P2122 Throttle Pedal Position Sensor Switch Circuit Low Your best bet would be to take it to a qualified repair shop .

had the same trouble with my '10 impala it turned out to be defective electronic accelerator pedal it is actually a recall for this vehicle and should be a free repair at your dealer.

Hi Rosalee_IM,
The codes your vehicle is storing are for low voltage from your accelerator pedal position sensor and a gross evaporative emission leak. The code P2122 and P2138 are directing you to test the accelerator pedal position circuit and/ or sensor. This is the cause of the reduced power concern you are feeling.The P0455 is telling you there is a large leak in the evaporative emission system. The most common cause for this code is a loose or incorrectly installed gas cap.I hope this helps clarify the concerns you are experiencing. If you'd like more information on how to trouble shoot the problems,drop me a line. Please include the model Impala you have,(LS,LT or LTZ) and the engine size. I will do my best to get back to you as soon as possible.Thanks, Chuck

how do you fix the "reduced engine power" light on the dash bard of a 07 Chevy Impala LTZ and "Service Traction Control"?

It sounds like these things are all related. When the a computer sees a problem in the Electronic throttle system, it will dissable traction control, and give the reduced engine power alert because the powertrain computer does not know the value of throttle postion.
Codes will need to be scanned in the computersto begin diagnosis.
TechJK