This is a really tough question.... All I can say for certain, is that is depends. The DMV in Cali is similar to the Iraqi Republican Gaurd. Everyone lives in fear of them, but when it comes down to it, they are as disorganized and worthless as a group of people could be....
The system can be very messy....
The things that will affect the cost and ease of registration include, but are not limited to:
1. is the vehicle a "built for cali car" or a federal car
2. was it ever registered in cali
3. is the VIN still in the DMV system (if not you will most likley have to have the vehicle safety inspected by the CHP as well)
4. Is the engine in the vehicle the stock motor
5. Is all the factory smog equipment still on the engine, does it all still work
6. etc., etc., etc
Having friends in the smog business would be a big help....
Having a "buddy" at the smog referee station is even a bigger help....
I would go to the DMV with the pink slip, find out what they require (sometimes you get lucky and they don't ask for much)... and go from there...
In addition to the good info in the above reply, if you are buying the vehicle in CA, it is the SELLER'S responsibility to provide a smog certificate. Of course, if you are bringing it in from another state, then it has to pass both visual and smog tests. By late fall, the tests will be done on a dynamometer in my area, depends on where in the state you are, how the test is done.
Most smog folks aren't too up on TLC's and will verify the evap. emissions and the EGR, and then do the tests. Until my '74 became over 30 yrs, it would pass well, usually with a comment like' boy this is clean'. That's because I was running a '78 2F instead of the '74 F engine, with all the '78 2F smog gear, but they were checking it against '74 required performance specs.
The best advice I can give you is go to a place that does a "pre-test". This will cost you about $30. If you fail, you can fix it with no harm done.
But if you fail the actual test, you will be labled as a "gross Polluter" and you will have to smog yearly from then on. If you have all the smog gear
You'll likely be fine if it is well tuned prior to the test. If you have headers, you will fail the visual. If you lack major pieces like the air pump or
converter, you will fail even before they hook up the machine. The key is to go in and pass, and not get in the ARB's data file as having previously
failed. My buddy is involved in this scenerio now, and his life sucks once a year at smog time. Mine hasn't failed yet and I only have to feel the pain
once every 2 years.