So according to you anybody who has modded any car with any type of smog controls is illegal?
Strawman argument, I never said or implied such a thing. You can mod a car any way you want as long as you don't disable any of the emission controls and use approved parts. There are many OEM and aftermarket performance parts that have been given the A ok by both CARB and the EPA for low emission cars. If the turbo kit you asre thinking of has a CARB number making it legal, then it is, I can't read your mind to know what model number kit or brand you have in mind.
Sadly the government has the power to break it's own laws, me and you don't have that power and you can take that risk if you want to.
I never said LS swaps are illegal, I said most that I have seen are not performed legally, many don't install cat converters, the enhanced Evap, even placing a carb on them, etc voiding the legality of the swap. You would think some companies would make pressursized gas tank to retrofit into old cars to make junkyard LS swap legal. The fact of the matter is without installing a pressusized gas tank and pressure sensor, your junkyard sawp in illegal, not somewhat legal as there is no such thing, just illegal.
Doesn't matter how much you drive your car either, a car parked, not running emits lots of HCs out of the gas tank and fuel system just sitting. The Evap system, a closed venting system, captures all the gas flumes and stores them to be burned by the engine when you start it. An enhanced Evap keeps the tank under pressure so if the pressure drops, the ECM knows there is a leak in the Evap and thows a code. That is why leaving a gas cap off a modern car sets a code. So as far as Evap is concerned, it doesn't matter that you drive 1K as most of your HCs come from sitting around and improper Evap control just lets them lose and create smog. With a disabled tank pressure sensor, the inspector can't test for leaks in the Evap and is a automatic fail. Anything that prevents the inspector from insepecting a car, from a burned out SES light to a cover over a ALDL port is a automatic fail.
As for exempt, that means you are only exempt from reguler testing, not from obeying the law. Some states still pull spot roadsides checks, forcing everyone off the road to be inspected. Also any time you get pulled over, a cop can cite you to report to a inspection station if he or she suspects illegal mods or doesn't like you, even if you have classic tags or otherwise exempt. Because you are only exempt for reguler testing, not from surprise testing.