a6 exhaust
 

hey guys im kinda confused on what to do with my exhaust. DPs and catbacks are outragious so im kind of thinking about just 2 3 inch straight pipes after my cat or i was looking into exhaust cut outs but im really pretty confused here. I am on a tight budjet and am not to concerned with what nets the most performance i just want like a fairly loud good sounding exhaust but i know it will be pretty quiet no matter what since im completly stock

What will net the most performance is Downpipes. The stock downpipes have both a PRE-Cat and a catalytic converter on one complete peice, not bolted together. Those Pre-cats are very restrictive getting new DP's opens them up (most manufacturers omit them all together), allowing your turbos to spool quicker and keep the temperatures down sustaining the life of your K03s. This is also something you'll likely want to do before chipping stock turbos so its in the best order of operations as well.


Check Vast Performance for Piggie-pipes (stock pipes which have had the pre-cats gutted out and refinished).

or check 038motorsport and SSAutochrome. Both have the most afforable options IMO.

Replacing your downpipes will also prevent any stupid p0431/2 and other warm-up catalyst engine codes.

Uhhhhh.... You mean it will automatically throw one... not prevent one...

With piggies the bung for the O2 sensors are replaced downstream to prevent it dude.

Most aftermarket downpipes also have the bungs either with non-foulers or replaced to new locations. If you have a gut the pre-cat and have the sensor in the same place you'll throw a code ya.

Check with Vast, they move it post-cat so this doesn't happen.

More than half the people that I know with piggies get pre-cat efficiency code after they installed the piggies. Most result to non-fouler setup. Moving 02 sensors down stream will generally not deal with the code, not to mention the factory o2 sensor wiring is not long enough.

Perhaps you can confirm this, but if my memory serves me correctly, the stock pipes have a pre-cat 02 sensor before the pre-cat... and a main cat 02 sensor before the main cat. Which basically means a measure is read before the pre-cat and after the pre-cat... taking no account of the Main cat's readings.

Due to this, most aftermarket downpipes/headers have no pre-cats at all, and the 02 sensors will be before and after the Main cat. This eliminates any warm-up catalyst errors and provides actual main cat readings.

You are right. I thought you were strictly referring to getting rid of the pre-catalytic converters.