90db exhaust noise limit

[DreadAngel]

Both the resonator and muffler are there for sound reduction...

But for RWC, check their documents, should specify what they consider is necessary =)

[mooshie]

Cal, roadworthy only means the exhaust needs to be in good condition with no leaks or rust etc and exiting to the rear of the passenger door openings.

Roadworthy is not a dB check on the car although if the car is excessively loud then they are likely to not let you through. So to answer your first question specifically- no.

You can run the risk of what 'excessive' means to the inspector! If you can advise what state you are in as well it would help, as most states are very different when it comes to what actually happens at an inspection. What I refer to above is just a generalisation of most rwc processes referencing the ADRs.