2000 buick le sabre 3800 series II

What is your question?

When the car is in park if I step on the gas slowly it will steadily rise at a constant pace. If step on the gas at a fast pace the rpms will jump up and down 1000 rpms when it reaches 3-4000 rpms and the engine shutters really bad. I tried replacing the coil packs with a used one and it didn't help. could it be the plugs or wires. I also could be the cat My code reader had 11 different code for maf sensor, multiple misfire, rear o2 sensor, and one said to replace the cat