So my MIRA(2010) started making heavy exhaust noises and gradually became really under-powered.I serviced it, changed it's gear oil but nothing happened. Then I went to Toyota Service Center and they told me that I need to change the catalytic converter. They don't have it with them so now I have to go to Bilal Gunj and get a 2nd-hand one .Any suggestions on what should I do and if I'm searching for a 2nd-hand one what precautions should I take. Thankyou