so i have a nasty rough idle and gas mileage sucks, ive changed plugs, wires,cap n rotor, cleaned tb, and now i hear my cat. could be plugged up, can i check this or do i just got to go out an get a new one. also many of people told me one of my o2 sensors might need to be replaced, and nothing comes up on my scanner so im not changing them ifi dont need to.

 

Typically, if you can hear the cat rattling, it is on its way out. If your catalytic converter is plugged, it can foul the O2 sensor.

 

thank. ill replace cat. an the sensors an hope it will fix my problem

 

plus if the cat is going out your engine is struggleing to operate. It cannt breath well. Like trying to breath through a straw while running a marathon.