It is illegal to tamper with or remove an emissions control device. If the DPF is removed your vehicle will not pass an opacity SAE J1667 Snap-Acceleration Smoke Test Procedure used for roadside inspections in most States. In Ontario diesel trucks are subjected to a more comprehensive and accurate exhaust gas analysis to meet emissions standards. Your truck will not pass the emissions test with the DPF removed. The fines vary for each province and state. In Ontario the fine is approximately $500 and in some states fines can be thousands of dollars per offence. If you run in California, it’s important to know that fines can run as high as $10,000 per day per offence.