Ok, I don't know if this has been posted anywhere but here it goes. How many years before my car gets a smog check? I live in California and I bought my brand new Duratec PZEV Focus back in 2003. now after 100K and five years later they haven't asked me to smog my car. I just pay for the registration and that's it. I want to know because I want to put the header in my car. will it be on the 6th year? Thanks in advance for all your input.