I'm looking for a CARB legal exhaust for my DB1 anyone know of one that'll fit a 1990 integra 4 door?

 

Any exhaust will pass smog inspection if all your sensors, cat, and engine are in good condition. California limit is 95 decibles, smog stations don't check that though. Only Cops can give you a state ref ticket to get your modified exhaust tested to see if it is under the 95 decible limit, smog stations won't test your exhaust during a smog test.