hi there...

well besides the bunch of $%#" problems my car has (high fuel consumption, probably misfire.. etc etc) now my car is making a horrible sound every time i turn my air conditioner on,
its like an old mexican taxi sound like "prrrrrr" but VERY loud, from the exhaust, and my car is totally stock, i dont know if i just have to change the muffler, i mean when the a/c isoff the car sounds a little more than usual but with the a/c the motor sounds more (because of the air compressor i think) and the exhaust gets REALLY loud... and with temperatures as high as 40° C (dont know in F's)and my window motor working only sometimes there's no way i can avoid ac this summer! :p
hope u guys can help... thanks

The A/C might kick up the vibrations, and causing the heat shield on the catalytic converter
to rattle, not a big deal really if thats what's happening.

huh i dont have cat xD but i believe the sound comes from the pipe itself... is it normal that our cars make a lot of noise with the a/c? what else could i check or change?

yes our cars make alot of noise with the a/c on

a little more so with motor mounts