It is now time to perform the emissions test. After entering your drivers license number into the emissions machine, the machine will tell you to scan the vehicle registration. This is why you verified its expiration date in the first step. From there follow the directions on the screen. It will have you enter the vehicle year, make, model, transmission type, registration county and GVWR (gross vehicle weight rating) if its a truck or minivan. Then you will have to perform the gas cap test. Connect the gas cap to the proper adapter located by the testing machine then connect the emissions air hose. begin the test and the machine will apply a set pressure to the gas cap to ensure it isn't leaking. When that is finished, connect the DLC(data link connector) to the DLC in the vehicle. This is the rectangular connector usually located on the driver side foot well, but some European cars have them on the passenger side or integrated into the center console. Start the car and press enter to begin the test and the machine will scan the car for any problems while it is idling. If all goes well, the test will be over in less than a minute and you will start writing the emissions sticker.