so if i saved up to get a full turbo back exhaust either from APR or Neuspeed, would it pass the smog inspection?

 

No, a full turbo back exhaust is even less likely to pass smog check, because with such a setup, it would be even easier to tell that your A3 is modified.

 

So i just might as well just get the downpipe then, since i don't wanna be loud riding down the st anyways.

so SHOULD i get the downpipe?

 

It's all up to you. At ecode it's approx. $500 installed (w/APR Stage II reflash). Stage I not fast enough for you?

 

I don't know that it's totally accurate to say you are more likely to fail smog tests with a full turboback... you have a couple scenarios we're talking about here:

1) Replace downpipe with a cat-delete pipe
2) Replace downpipe with a high flow cat pipe (still has cat)
3) Replace with full catback + option #1 or #2 above.

I'm no smog check expert (last car i did it with was when i was 17 in an '84 buick century - yeah it had the vinyl top), but i understand the process to be: a) visual inspection and b) hook up the hose and test the exhaust.

I think what A3_yuppie is saying is if you do option #1 above, you will likely fail the first level of smog inspection and have no chance for part b (this assumes your cat delete pipe appears to have no cat - whereas the downpipe that started this thread looks like it has one, but doesn't, and can be retrofitted... so with that option, you may pass part a). if you do pass part a in that scenario, i don't think you'd ever pass part b with no cat. hope that makes sense.

The other option is to go with option 2 (with or without catback). while you have a high chance of raising suspicion in visual, i believe certain high flow pipes are smog compliant (there are 200 and 400 cell pipes out there).

most of what i am saying is based off an s4 setup as i haven't yet done any major mods to the a3. a3_yuppie or others, please clarify if i am off base. nonetheless, unless CA is different than WA, it's a moot point for the first 5 years of the car's life - unless of course you are looking to be environmentally concious as well.

 

so if you fail a smog test, what happens?
i can't reregister my car?
or can i just pay the smog test guy a few extra bucks to tweek the test so i can pass?

 

The ATP downpipe does not have, and does not even look like it has, a cat.

The thing is, for the visual part of the smog check, if the part looks aftermarket, the tester is supposed to look for a CARB EO (exempt order) number. None of the aftermarket downpipes to date have this.

Like I said, you don't have to do a smog check during the first five years of ownership though. You can always reinstall the stock downpipe before the smog check.

In CA, the police can pull you over (w/ reasonable suspicion) and see if you have illegal modifications, i.e., aftermarket downpipe (w/o CARB EO number). This is more likely with the rice rocket crowd (no disrespect intended, I had a few myself). If you do, then it could be anything from a fix it ticket to getting your car towed. In these cases it is generally better to have at least a stock-looking part.

Not to mention, from perusing this and other forums, Stage II folks seem to run into more trouble with CEL, DV failures, etc. than Stage I folks.

 

CEL, DV failures? what's that?

 

check engine lights, and diverter valves failure. You may want to ask A3Night about how to crawl under your car and see if you have the C diverter valve.