Hopefully your fiancé doesnt make you return those after I swing by this evening haha! ;D
You’ll like 034’s motor mounts, very happy with mine.
Drob Im sure jake will step in but to help with your questions.
The one outside flang welds are just set up welds to hold the flang while the inside part is welded. When you look at the inside where all the exhaust goes through its solid welded. So dont worry about the outside welds those are just set up welds. The inside welds around the flange and the pipe really look good.
As for the 02 bungs first off. WOW do the 034 units look like complete shit. But the two bungs on the pipe would be for the primary o2 at the top and then the secondary o2. They are just located in the same pipe. You shouldnt have to cap anything.
Makes sense about the welds. Thanks for the reassurance. I was pretty sure the primary O2 was on the exhaust manifold but I could be wrong. Only saw one sensor on the factory cat.
Do you have a recent dyno baseline so we can get a before/after on the gains of catless. I suppose it’s more a rearrangement of the curve rather than an outright gain (weaker down low, stronger up top).
No I don’t.
Doh! Looks like our fabricator accidentally gave you got an extra bung! Most people have to pay extra for that 
I will ship you out some bung plugs. You should have them by Sat.
As for the welds, its a cool technique we use. It also improves the strength!
OK please do Jake. I’m dropping off the car on Sunday so would make my life a lot easier if they get here by Sat. No worries about it though, I figure if I weld a cat into the downpipes and move the O2 sensor behind it to pass readyness, I would need to plug the bungs anyways.
Out of curiosity, why would someone want a second bung?
And please all, no bung plug jokes 
http://www.boxofficemojo.com/image2/bruno_5633_D011_00047R.JPG_cmyk.jpg
wideband option would be my guess.
What would be the advantage of running the wideband O2 on the testpipe instead of the factory location on the manifold?
Haha yup, people want wide band gauges for AFR.
A wide band gauge will need its own bung and has it’s own sensor which is why an additional bung is added. You Basically got $80 bucks of free bung/labor.
I guess a “down the road” mod can be a wideband sensor haha (in theory would work well with my P3 8))
Wide ban would be cool but you would rather have a EGT gauge thats going to tell you just how much heat the motor is putting out and give you an idea on what your dealing with. I suppose you can have each. Just put one in one side and one in the other
The P3 gauge does provide an EGT measurement, though I have no paid it much mind before. Everything the P3 displays (expect for boost) is a PID signal on the OBD bus (same thing you would read with an OBD data logging dongle - but not the same as VCDS advanced measurement). So the EGT measurement is probably whatever the ECM uses for engine controls and feedback. Not sure exactly where that sensor is.
You are definitely correct about being able to run one on each side. I would need whatever cheap sensor interface connects to the 0-5V P3 analog input. I’m assuming a sensor would need/provide +12 V, Gnd, 0-5V signal.
Moved this post here to avoid derailing clochner’s new ride thread 8)
So could I put these mini-cats in series with the secondary O2 sensors and not need to run a test-pipe APR file? Would save me the time/labor of reflashing the test pipe file. Plus the car would in theory clear readiness?
Also, anyone have a recommendation on a reasonably priced wideband O2 sensor (UEGO ) that would interface with the P3 gauge (0-5V)? Similar question for a EGT sensor. Appears that the P3 EGT signal is going to be calculated and not a true temperature measurement.
you can try those 02 units on the car but I think one of the issues with the new cars is that you will get a slow 02 code. Those dont look to dramatic in there size so you might be good.
Some work better then others. I know some dont work at all for the b6 and b7 s4.
Hmm ok thanks, I’ll just flash the test pipe software and worry about emissions testing if I ever move to a state that requires it.
Surgery underway
https://farm1.staticflickr.com/554/20502206891_d9b26191e3_b.jpg
https://farm1.staticflickr.com/343/20487108472_90406c6857_b.jpg
Its great to see your getting the car fixed. But its a bit extreem to have the motor out of that kind of fix isnt it.
yea was thinking the same