AOA,
I simply dont agree with whats being said here, I bought 2003 Vitz back in 2006. Odo at that time was 46,000kms.
Since then its being used in Pakistan, on super petrol that is available locally (adulterated as PW's say).
Car is maintained by Toyota Garden, the odo is 116,000kms we never had the cat choked.
Dont spoil you car buy taking out Cat Convertor, take it to 3S dealership for tuneup and happy motoring.