409ss last a long time but will rust. Most makes use aluminized steel due to cost and it should last through most of the cars life.

 

aluminized steel in my experience rusts after a year and prolly rusted thru in 5 yrs if you live in a salted snow area like pa, no one would buy stainless if aluminized steel lasted, i had HPC + JET HOT coated headers in the past, peeled after 2-3 yrs than the ugly rust came etc!! i keep my cars a while as the 01 jetta bought new, just traded 199XXX with same 304 unrusted stainless exhaust but thats just my experience, live in arizona any exhaust prolly lasts longer

 

Ok so I got the new exhaust and installed it last night as well as the intake, stage 2 tranny mount and dogbone...left out the motor side mount for now but have it.

To my surprise the exhaust was completely broken off at the flex pipe. Never thought I would see that but at least I was correct in the problem.

I do however have a question that maybe I can get some help with here. The new 3" exhaust has 2 02 sensor bungs on it which is what I figured the car would have however that is not the case. There is actually three on my car. It is a 225hp just in case that has anything to do with it.

I have to order that rear 02 sensor as we couldnt get the old one out of the old exhaust. Tried everything. The one or two in question are the rear sensors. If it had three and i only have spots for 2 which 2 do i use and what do i do about the other one?

2 of them have 4 pins and the third which should set between the pre cat and post cat has 6 pins. I assume thats the heated one? I need to know so I can order the correct one and if there is an issue I can call 42dd.

Thanks

 

Well just got off the phone with Audi. It looks like the third one goes to the air to fuel ration gauge that was installed in the car before I bought it so I didnt know what it was. The gauge has never worked so I am going to just leave that one out.

Oh btw the new exhaust sounds amazing especially with that intake from 42dd. Gonna have to get used to the new noises from the exhaust and intake!

As a note to what people had mentioned to do to get the dp out...mine was easy as cake even after 160k miles. The only big issue was getting the downpipe to clear a stud that came of the exhaust manifold. Had to grind the new exhaust down slightly to make sure it would clear that stud going in.

 

your saying you installed downpipe on a MK I 225 hp quattro without dropping subframe, could you elaborate on the installation a little, i know the 3" downpipe car release some power for sure, did you use a catted version. as stated my past experience with coated headers holds me back on what seems to be a nice setup from 42DD, i KNOW 304 stainless will LAST, as i intend to keep my "new" to me 37xxx mile 2001 TT forever as i recently retired and do not drive as much as when commuting on construction as much as 1000 miles weekly