Take the advice of 69Boss302 and others, just replace your precats with msds headers. You can get them for under $600 and pass smog no problem. The precats are only for when the car is cold, so all you have to do is take a decent drive to warm the car up before you go in for smog. Many people have passed with them in CA. Your main cat in probably fine, no need to touch that.
Basically, going with headers will be easier, cheaper, and give your better performance. Although in Cali you'll have to put them on yourself or have friends do it since no shop will touch them.
