Car has no power when driving

I suggest you read the article at Reduced Engine Power Warning: What Does It Mean? - In The Garage with CarParts.com

This has nothing to do with the Catalytic converter ! Plugged catalytic converters don't go away after shutting off the vehicle !
This reduced engine power has to do with the
Throttle Actuator Control (TAC) System
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:
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Acceleration limiting--The ECM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.

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Limited throttle mode--The ECM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.

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Throttle default mode--The ECM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.

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Forced idle mode--The ECM will perform the following actions:

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Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off.

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Ignore the accelerator pedal input.

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Engine shutdown mode--The ECM will disable fuel and de-energize the throttle actuator.

I agree that all this new technology could have been used to make life easier instead of which it has been deliberately and calculatingly misused to make life harder and more expensive.

I suggest obtaining and using an obd recorder. The dealer might have one to loan you.
Plugged into the obd port it continuously records engine management conditions and data to be reviewed later on a standard laptop or desktop computer. It might need an expert to understand what is happening to cause the fault but sometimes that is the best or only way to find an intermittent fault.

There is one condition that can affect some engines without being recorded as a fault and that is a turbo over-boost condition caused by the incorrect operation of the turbo wastegate. This is generally a control or sensor problem and instantly kills the engine power when it happens. Switching off the engine and restarting allows normal driving again until inadvertently too much acceleration is used again and the cycle repeats.

I hope this helps.

The automotive trouble code P2138 throttle/pedal position sensor/switch D/E voltage correlation refers to a problem related to the throttle's ability to open and close properly. Replace (suggest) the sensor (black object) on the throttle body.

Have the vehicle checked for DTC'S - diagnostic trouble codes ! Do you know what electronic throttle control is ? The gas pedal assembly has electrical connector an sensors inside ,hooked to the PCM / ECM - engine computer . The engine computer uses these position sensors inputs to control the DC motor on the throttle body to open the throttle plate to control the speed . Plus there are position sensors inside the throttle body to input PCM/ECM to see if it's calculations are corect . Your best bet maybe to take it to a qualified repair shop .
Drive by Wire Function and diagnostics by Wells

Reduced Engine Power Mode
When the PCM detects a condition with the TAC system, the PCM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:
• Acceleration limiting--The control module will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
• Limited throttle mode--The control module will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
• Throttle default mode--The control module will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
• Forced idle mode--The control module will perform the following actions:
- Limit engine speed to idle by positioning throttle position, or by controlling fuel and spark if throttle is turned off.
- Ignore accelerator pedal input.
• Engine shutdown mode--The control module will disable fuel and de-energize the throttle actuator.

sounds like the camshaft sensor or the crankshaft sensor, either way I think your car is being recalled for a faulty ignition switch which could turn off by itself.

With the oil light coming on and the brake pedal being hard to press I would say that the engine stopped hence no vacuum -no power assist from the booster.- hard brake pedal. The lock uo feeling may come from the engine seizing up while you were still in gear

clogged cat

Could be the fuel pump in the Gas tank. Mine crapped out and caused the car to have reduced power for awhile before it quit all together.

The reduced engine power happens because there is a problem with the electronic throttle control . Some people call it drive by wire ! The gas pedal has sensors inside , position sensors , connected electrical to the PCM - engine computer , the throttle body on the engine has a DC electric motor an also has position sensors . These are also connected to the PCM electrical . The PCM reads the position sensors which indicate how much your pressing on the gas pedal . then hopefully it opens the throttle the same amout .

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)

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.

GM Electronic Throttle Body Circuit Descriptions And Testing Tips

Tons of videos on youtube for these systems , there can be a variety problems , from wiring , worn out sensors , the DC motor , computer etc....