anilll

hello everyone,
i'm Anıl,i m from Turkey and i had a 2003 chevy trailblazer.Reduced Engine Power Light sometimes came on while driving ,the car didn't stop but i can't pass 2000 rpm and i hear sounds like boom interruptedly while reduced engine power light came on.Sometimes it didn't come on,but when came on once,i rerun but the light came on a few times and the car went to safe mode.I rerun when the light came on for go home .When i rerun the engine the Light go out and i can drive it normally.I changed the spark plugs yesterday because the car knocking and one of the spark plug's nail broken.The exhaust had broken from inside and when the engine is idling ,sounds like 'tick tick tick 'came on from exhaust.We test the car with computer and APP1 sensor faulty.We searched and we find this ''Between The gas pedal and the are in miscommunication.I have questions for you..Can these situations can relevant with catalyzator?Can it clogged?Should I change the gas pedal ? Can the sensor out of work ?The car knocking in first gas.Yesterday,we cleaned the throttle body.Should a space between in it? Because i saw a little space in it. When i accelerate hard,sometimes the car accelerate fast but sometimes slowly.Can you help me ? Thanks for answers.