gman73

SLP LM will not fail smog. They are 50 state emission legal. But they are not 50 state sound legal.

Thrashard340

Agreed. There is nothing about a LM that will cause it to fail visual and mechanically, it won't alter the sniff test.

Here's my take on altering exhaust in CA...

I have a coworker with a 2003 Mustang Cobra. He had Bassani x-pipe, race exhaust and hi-flow cats. This set up failed the sniff test. He ended up having stock cats put back on the car before it passed smog. It was an expensive lesson for him and he regrets ever putting those hi-flow cats on. My recommendation is install hi-flow cats at your own risk. Some may pass smog, some may not.

As for noise, someone posted db limits and that's pretty accurate. However, every city decides differently on whether to enforce it. I live in Union City and law enforcement doesn't really care. If you go over one town to Fremont, it's a different attitude. Fremont will scrutinize mods. Exhaust is a common way to draw dirty looks or get pulled over in that town. My recommendation here is to get to know the law enforcement in your city.

moose_knuckle

Oh i guess i understood wrong. Ive never had to have a smog test before. I live in San Jose and dont really get messed with my exhaust noise from the cops. I was just worried about passing smog....