If your state or jurisdiction requires a visual inspection and you have removed the DPF, CAT and/or EGR you will not pass. Be sure to install all the factory emission components prior to testing. Other states which perform an opacity test; its recommended you bring your vehicle up to full operating temp and set your RaceME to the lowest power level prior to testing. If your truck is in good mechanical condition, 99% of the time you will pass. For those lucky enough to live in rural cities or states like Texas which perform "safety inspections" your in the clear.