Thanks for all the great info.

 

Taking the CAT off is definitely illegal. As far as just taking the muffler off, it depends on how loud it is. There are vehicle codes covering noise and decibel levels, etc.

 

Not only NO (Its a violation of the FEDERAL Clean Air Act), but HELL NO in California (CARB). CARB hates diesels, has declared them to be the spawn of the devil, responsible for most all of California's air quality problems, and would ban them completely if commerce wouldn't stop if they did.

CARB doesn't even like biodiesel, because it puts out a bit more NOx than #2, although it's cleaner in all other aspects. CARB is probably the real reason that the EPA mandated emission devices for diesel in the 1st place.

OMC

 

If you remove the cat converter, it is illegal in the USA. Last I checked, California was part of the USA, though sometimes I wonder .

I don't know how the laws will change in the future, but today there isn't currently a requirement for any kind of inspection or test that will result in a removed cat being detected by the authorities.

However, I have been burned at least three times by retroactive laws being passed that made a past decision choice a poor one (stuff once legal now illegal or highly regulated), since I move to CA. As a result, I personally won't modify any vehicle's smog equipment without the change being CARB approved.

 

I would say it would be illegal to do that in Cali. From what I hear and read , the smog police are very very strict. Im sure some one else with tap into this thread with better advice.