As we al know the catera is a great car when nothing is going wrong with it. Well my 99 catera's check engine light came on for the first time about 2 days ago. I got the code read and it was the P0455 code " evap emissons control leak large". The car is running just as good as it was before the check engine light came on. My gas cap is also tight so I know its not a loose gas cap. I went to my local mechanic and they told me that they would put the car on the diagnostic machine and do a smoke test for 115$ to find out where the leak is. My question is, should I spend the money for the diagnostic and smoke test, or is there a easier way??? Not to mention my state inspection is right around the corner.