New owner here - couple of quick questions:

- Is it acceptable to run a catless downpipe / test-pipe with everything else being stock with no ill effects? Just want to make sure I don't need a "tune" or anything at all in addition.

- What are the recommendations between full length downpipe vs. test pipe alone.

- What type of gains can be expected of each?

- Who makes a good quality of each? Who is recommended?

Any guidance or reference is appreciated.

I am not interested in turning up the boost- yet. Just want to free up some easy hp. No inspections here

Thank you

 

Dang bunch of views but no responses?? Does anyone have a test pipe or downpipe? Let's start there.

 

Since you're new here, I'll just help you out a bit. This is a great place to come for info, but it's not the speediest forum out there. You can generally expect it to be a day or two before you get a response on a new post.

Generally people running test pipes are doing it BECAUSE they tuned their car. Not sure why you'd bother with one if you didn't. That's not to say you can't--just that you may get a lower than average response time due to it being such an odd request.

 

Gotcha - thanks for the info K

I just wanted to be sure the lack of a cat and stock ECU would not cause a problem with AF ratio.

Every turbo car I have ever owned responded very well to a well engineered downpipe or just removing the cat so I figured the A4 would be the same.

Now I just have to figure out the most reputable manufacturers/tuners that offer such a downpipe.

 

The forum was much more active when our cars were newer. Now that they've aged traffic for the B7's has slowed. Also remember by putting in a downpipe and getting rid of the cat, you are making your car illegal. While your area might not test, it still might also cause issues with warranty or trading in/selling in the future. Remember the emissions warranty is to 100,000 miles, and the cam follower/fuel pump 120,000 miles. By modding the car you could void those and be in for huge expenses. I was fortunate when my cam follower went it was covered, since I had to get a new fuel pump, both intake and exhaust cams, as well a new head. I don't even want to think what it would have cost if I had to pay for it had I voided the warranty.