wazzup yall 7sifu...normaly if yall change da back box exhaust wut happend with da catalytic converter...did yall change to new one or just take it off??ist ok to take it off or just leave it there?..coz i read one article from motor trader,da catalytic converter can tahan only 5years n after that have to change new one..ist true??if true wut is da money like??or ist ok if didnt use it...pleasee 7sifu i need a guide here...