OK so I did notice something different. please tell me if this is my imagination or if this is a problem. Before I got the CEL when I pressed the gas pedal while in park to rev the engine, it would get to let's say 4K rpms and the go down again regardless if I kept the pedal down, now when I do that it holds it up there as long as I hold it down. Is this normal?

p.s. the CEL was not on today but I guess I'll change the sensor anyways cause it's probably going bad.