Catalytic Converter / Low Sulfur Diesel etc etc. are all made to control & handle environmental situations for countries such as U.S, E.U where it's totally ILLEGAL to remove a catalytic converter, and if you do so, u will have to pay 1000's of dollars for polluting their country environment.
Catalytic Converter is simply a LAME USELESS material. its a BIG BLOCKING BARRIER in your exhaust system!!
Some engines are designed in such a way, have chips/I.C's to detect the removal of ur catalytic system as international standards, so a person doe'snt removes it, it warns you, but that all warning is useless & non-genuine. Remove all catalytic connected i.c's & circuits to let ur vehicle run on standard otherwise ur i.c will keep telling the fuel/exhaust system via wrong back pressure etc etc. Removal of those circuits is very necessary before removing catalytic converters, esp in new cars.
& if u dont maintain ur catalytic converter on TIME, it gets HEAT up. LOT OF HEAT!! it can even reach upto 500 Degree Celsius, causing harm to your GEARBOX system.
Concluding, Simply Catalytic converter in Pakistan is a PAIN in da BRAIN! REMOVE it & Enjoy simple engineering! 