Impala reduced engine power

I understand your concern regarding the Chevrolet Impala's engine performance. I once encountered a similar predicament with my previous vehicle, a 2014 Opel Insignia, experiencing identical symptoms and error codes. Have you inspected the wiring harness and connectors associated with the throttle body and accelerator pedal? Did you notice any abnormalities in the engine's behavior prior to the onset of these issues?

Thanks for the quick reply! I checked the wiring harness visually, and nothing jumps out. I didn't touch or disconnect anything, though. Would a deeper dive into the wiring be worth it before I throw parts at it? Regarding prior issues, sometimes the engine was a bit jumpy during cold starts, but otherwise, it ran smoothly. Could that be related?

Based on the information provided, it is plausible that the cold start issue is connected to the current predicament. Given my experience with the Opel Insignia, I recommend seeking a professional diagnostic assessment at a reputable workshop. It is conceivable that a faulty sensor or electronic component within the throttle body is the root cause. Repair costs are likely, so be prepared. I ended up replacing the throttle body on my car.

Thanks so much for the advice. I took it to my mechanic, and you were spot on. It was a defective throttle valve. They suspected either the accelerator pedal module or some internal electronics were fried. The final damage came out to about 265€ for the replacement and labor. Runs like a champ now!