Why does reduce engine power light comes on chevy

codes OBDll and available on free.
example P1516 code
https://www.way.com/blog/p1516-meaning-symptoms-causes-and-fixes/

https://www.engine-codes.com/p1516_chevrolet.html

https://www.troublecodes.net/p1codes/p1516/

have the fault codes read and fix the fault that put the ECM in limp mode
reset the ECM on completion of repairs

2010 Chevy Cobalt code P0641 Yahoo Answers

Sounds like your crankshaft sensor is bad. It will stop working if bad and will leave you stranded. GOod luck.

As far as the cobalt, check tac/throttle actuator control. Below is circuit description for p1682.
The other codes was for knock sensor.

The check engine light being on now is a different problem , Have DTC'S - diagnostic trouble codes checked ,will have something to do with electronic throttle control . That is what reduced engine power is about . It's in a reduced power mode.
Reduced Engine Power Mode
When the ECM detects a condition with the TAC system, the ECM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:
• Acceleration limiting--The ECM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
• Limited throttle mode--The ECM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
• Throttle default mode--The ECM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
• Forced idle mode--The ECM will perform the following actions:
- Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off.
- Ignore the accelerator pedal input.
• Engine shutdown mode--The ECM will disable fuel and de-energize the throttle actuator.

Do you know what electronic throttle control is ?
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Throttle Actuator Control (TAC) System Description

The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions:
• Accelerator pedal position sensing
• Throttle positioning to meet driver and engine demands
• Throttle position sensing
• Internal diagnostics
• Cruise control functions
• Manage TAC electrical power consumption
The TAC system includes the following components:
• The accelerator pedal position (APP) sensors
• The throttle body assembly
• The engine control module (ECM)

Your best bet , take it to a qualified repair shop .

reduced engine power message chevy cobalt 2006,cars sputtering, and when i presses on the gas the car wont move, i can put the pedal to the floor and the rpm's dont bulge

It should come out through the top. You may have to remove the hood and the radiator for it to fit.

disconecting the battery should reset the pcm. but you will need to find out what caused the problems.

i went to advance auto and they pulled the check engine light code and they said it was just wet electrical equipment from all the rain we have had and that it would dry out in a couple of drives so they reset the code and told me to come back in if it comes back on.