Unknown sensor will trip and give error code for misfire

Hello, I own an Opel Astra g 2000 thi 98 and, when driving on motorways at 75 mph, the car has no inconvenients but, when a slope appears, it loses strength and speed drops to 50 or even 40 mph. No matter how hard I press the accelerator, and not even changing to 4th gear, the vehicle does not respond. Once the slope ends, the car starts working properly again. I've already changed the flowmeter but it is the same way. What might be the problem? Thank you all.

I would like to know what it is that needs to be replaced, the computer indicates the following:
Sensors 1-2 correlation Accelerator pedal position / exhaust butterfly valve
Sensors 1-2 correlation Accelerator pedal position
Electric drive control Emergency starting butterfly valve
Relay/ Secondary circuit fuel pump
When warm, the vehicle does not accelerate properly and does not work as it should.

Hi, I do not know what is wrong with my car but, for some time, a light indicating the engine is damaged has been turning on. When scanning it, an oxygen sensor or lambda sensor failure is indicated. I've replaced it but the car is still the same. The EGR valve, flowmeter and throttle body have also been replaced but without any positive results. If anyone could help me, I would be really glad. Thank you.