Engine power reduced - Limp mode?

That is lean code usually caused by a vacuum leak that code does not go with the symptoms you described. A flashing check engine is usually caused a really bad misfire. Which would set a p0300 random misfire and or a certain cylinder misfire code. Also, when a GM car goes into reduced performance mode is caused by a throttle by wire fault like throttle position sensor fault the wiring itself etc. When the key is turned off and back on again if the fault is not there at time car will start and run normal again.

A bad coil coil will not set a lean code if a coil was not firing all the time you would get more raw gas going through the engine which is being combusted by the engine. The coil makes spark in the engine to cause the compressed gas to burn. A bad coil would cause the computer to set a misfire code. When there is a failure detected in the throttle by wire system the computer puts the car into reduced performance mode for a safety measure so the car does not possibly accelerate out of control. That is why I said just that code does not make sense for the symptoms. As far as those possible causes for the lean code most do not make sense. For that code restricted fuel filter low fuel pressure vacuum leak etc that would make sense. You can check the fuel pressure most the time when I see the lean code it is a vacuum leak somewhere. I have seen the diyer scan tool not read all the codes if some of them went into the history of the computer of the car.

Good morning,

This code be the throttle body or the accelerator pedal sensor that has failed and given you the low power indication.

https://www.2carpros.com/articles/engine-has-low-power-output

I would have the codes checked as it will narrow the area of failure for you.

https://www.2carpros.com/articles/how-to-check-wiring

Roy

ACCELERATOR PEDAL POSITION (APP) SENSOR

The accelerator pedal contains 2 individual APP sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
- A 5-volt reference circuit
- A low reference circuit
- A signal circuit

The APP sensors are used to determine the pedal angle. The ECM provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors provide the ECM with signal voltage proportional to the pedal movement. The APP sensor 1 signal voltage at rest position is near the low reference and increases as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near the 5-volt reference and decreases as the pedal is actuated.

The p0068 that is your reduced performance mode kicking in. How often does the reduced performance mode kick in? Because the p0068 code has to be active to follow the trouble for P0068 plus you would need a scan tool that can read live engine data as well. I would start by diagnosis that code first and go from there.

Yeah a lot of them these days are part of the fuel pump module. Keep me posted on how the car is running.