Hello. So ive had this 03 CTS for about 5 years. And ive had this P0440 check engine light on for a while already. Its about time that i think i want to get into debt and get a new car, however i cant sell this cts with a check engine light. Ive already replaced the gas cap with a brand new oem cap from the dealer, i erased my check engine light and light came back on. Im going to perform a smoke test in the car to find the evap leak, however i have no idea where is the test port on it. Where do i put the smoke nozzle? Can anybody show me a picture or point me in the right direction?