Downpipes/Cats (and CARB) Questions (in Cali)
 

I'm still new to Audi and am curious about all the hype about the HP that DP + catbacks can give you.

Do the downpipes on the S4 include the cat? Meaning if I get a downpipe, it will have a (high-flow?) cat welded onto it as well?

Any idea of the Miltek or Labree DP's have a CARB stamp? Or if they'll even pass the strict sniffer test here in Cali?

Re: None have a CARB stamp and the only one you can really get away with
 

is a cat back system. Any modification to the intake or cats are not legal in Comi-fornia.

but, my B5 S4 with Labree DP and MTM catback passed smog in San Fran

Re: None have a CARB stamp and the only one you can really get away with
 

I've always heard that with dp conversions, just make sure your car is really warmed up prior to testing. As the precats don't really do anything once the car is heated up. I might be wrong

Re:It will not pass a visual if they look for it. Also a CHP officer can give you a tiket if he
 

even suspects you modified the exhuast. Just because you pass a smog test does not make the system legal. CA VC state clearly what is legal and what is not. And by the way the CHP can impound your vehicle if they so choose(under probable cause) and take it apart to prove you guilty.

Re: The pre-cats do most of the work by becoming super heated. That is how
 

catalyst work, they super heat the exhaust to cut down on emissions at the tail pipe.

So does that mean they could pull you over and impound your car? Man that's scary.

And they do get hot. Gaddayum.

Re: None have a CARB stamp and the only one you can really get away with
 

Are the cats on the S4 part of the DP? Like if you buy a DP, it pretty much comes w/the high-flow cats? Or are they separate and you can buy/install them separately?

Re: The DP's mount on after the pre-cat. They only replace the secondary cats.
 

Which is still not legal in any way in Comi-fornia.