Hi Askari! Any modification to the exhaust system would require the approval of the Land Transport Authority (LTA). This is because if the exhaust system used or installed does not follow the vehicle manufacturer's specifications, the vehicle performance may be adversely affected and as a result, road safety could be compromised. Kindly refer to this LTA link for guideline: https://onemotoring.lta.gov.sg/content/onemotoring/home/owning/modification.html