Answer by yeahmeknows · Jan 31, 2011 at 03:57 AM
It's basically a test for your car that makes sure that the car is in "Legal drivable condition", meaning there is nothing wrong with the car as far as safety issues (lights, airbags etc..) and also they check if the car discharges no more than the poison amount allowed. Without your car passing a smog test you cannot pay your registration at the DMV and of course without those it's illegal to drive that car. You can read more about it here: http://www.dmv.ca.gov/vr/smog.htm
Also I must mention that not every state requires a smog check for registration renewal.
Hope this helps =]
Answer by iscifitv · Feb 06, 2011 at 12:58 AM
smog test is not a safety inspection or does it tell you its safe to drive! That is totally wrong. Smog is pollution, or emissions from cars . Smog test or smog passed means that vehicle has passed the states requirement for the amount of pollution (or crap) that is allowed out the exhaust pipe. Not ever state , or county in a state requires smog or emissions and it can be different as well. For example I live in Utah, but my city does not require smog control, however if I moved to salt lake city where it is required I would have to have my car tested. If it fails I can not drive in salt lake city. They have tags on your license plate to indicate your are legal. Now if I moved to L A California for example the smog control on my car would fail the California standards and I would have to pay to have my car emissions (smog) updated to meet the standard for Califoria (catalytic converter, computer, O2 sensors, ECM etc...).
Hope that helps.