Originally Posted by onzedge

Good question.

The level and type of modifying you do depends on a few factors. All of the mods I have done on my car are legal in CA, with the exception of my intakes. When it comes time to smog my car (about 4 years from now), I will replace my intakes with the stock units a couple of weeks before I take it in.

There are other folks who go further in their mods than I have and they are taking a chance, in my opinion. For example, if you replace the cats with test pipes and you get pulled over for noise (or another reason), you can find yourself in hot water if the officer decides to pursue it. Any non-CARB (California Air Resources Board) approved modifications to anything that impacts emissions is very bad to be caught with. At the extreme, your vehicle is impounded and at the least, it's a hassle.

It's up to you in terms of mods and how much attention you want to draw to yourself and how much risk you can tolerate.

These are my opinions only.