not sure if you want boost, or to increase power. if youre looking to boost, and pass smog at the same time, your better off with a supercharger/procharger so you can use the stock header. most people in cali will just swap their headers for their smog check, because if your precat fails, it could catastrophically ruin your motor. what you should do, is get yourself a catless header and some antifoulers, but KEEP your stock oem header intact for your smog checks. i know its a pain, to swap headers, but its been than frying your motor.