No, you have a noise limit on top of your emissions which will net you a ticket... PLUs (this sux but is fact) without the mufflers they won't pass you on smog, as it's (I kid you not) "missing components".
The muffler will not keep you from passing the sniffer, but will kill you from the visual, which they do before they do the sniffer probe. I got bit for lesser missing parts, and yea, they really honest to god look for this.
You can always switch out between tests, but you gotta be 110% right on the spot when you get your smog done. It's not just the garage being azzoles, but the state sends out snitches to make SURE they follow the rules, and will cost people thousands of $$$ and their license if they don't. And tey use cars like yours with parts missing sometimes.
Sorry, know it sux, but even if you have a street mauler, you need to have a smog-perfect setup to drop in for the test, else you'll never pass. Don't ask me how I learned this ;( . . .
Mechanic. Did smogs. Also ran "extra-legal" race cars on the street. Been stung for trying to fake the rules. Now spend the $$$ for motors, etc. to pass- it's cheap insurance to down a car for 2 days pre and post. Don't risk it, hon!!