Call around to different smog shops in your area, as I am sure you will find a wide variation in cost for the test. I live in Brentwood(CoCo County) and the first place I called wanted $100 for the test and a reservation 5 days out to smog my Dodge Ram 3500. I called around and found a place in Pittsburg for $35 with no reservation required and they have been doing my smog tests ever since. They also allowed me to observe them as the test was done. Kalifornia is looking for mods, missing emissions equipment, and excessive smoke.