Have any family living out of state. Have your registration address changed to maybe out of state? Not sure, since it's been so long since I lived in California about their laws. But, do they check engine codes now also when getting station checked? Hell, it seems they are pretty damn nosey nowadays and replacing the engine IMO is none of their business as long as it passes test. So glad I moved from that place to WA.
After a car turns 25 years old here, you can put twin blowers or jet boosters on your own car if you like. Smog checks are null after that period and beyond.