03 Corolla LE 175k miles CEL Error codes

[Ruskiy]

Hi,
I have 2003 Corolla LE with roughly 175k miles on it. Recently CEL went on and i got a friend to get me the error codes:

P0420
Catalyist / o2 sensor
P0110
P0120
P0100
Maf air flow
P0420
Catalyst / o2 sensor

P0420 showed up twice. Im open to hear any ideas as to why so many codes and what the problem might be. History on the car. It does have hole in the air filter on the bottom but i drove on it for a long time 1-2 years with no problems, sounds like an intake. I changed spark plugs not long ago. After the lights went on i changed the o2 sensor by the exhaust and cleaned the one by the catalic converter (or whatever its called). I swapped the maf sensor with my sisters car same model and reset the light. After 50 miles the CEL went back on. Any ideas how to fix this because it seems like it burning fuel more than before. I used to do over 350 miles per tank fill up. Recently did only 250.

Also, my engine, when warm, rumbles and vibrates the car more than my sisters during idle.

I have 5 speed manual, the clutch slipps occasionally and the tension bearing makes noise when i apply the throttle or roll in gear. Just wondering if anyone can give me some pointers or guide me through how to remove the transmission to replace the clutch, pressure plate and bearing?

[speedyts49]

I would look for vacuum leaks.
I had a 91 Celica and kept replacing sensors but it turned out to be a vacuum leak.
I have a 2000 Ford Focus (wife's) and it's CEL turned out to be a vacuum leak.
I have a '96 Tacoma that I did some repair on and knocked off a vacuum line causing a vacuum leak.

Check every hose is my advice.