Broken flange for catalytic converter A7 passenger side

[Valpo A7]

So I noticed a slight exhaust leak on the passenger side recently and read up on how to get the cat out to replace what I thought was just a gasket leak. Had it apart over the summer when I did my timing chains so I thought that maybe it came loose at the flange with heat cycles. Well that slight leak turned into a huge leak last night. Tore it down today to find that the flange broke off the converter at the exhaust manifold.

Build date was August 2012 for the car and it now has 206,000 miles on it.

That will certainly make tear down easier but now instead of a gasket it’s a cat replacement. Debating on replacement or repair at this point although leaning towards replacement. Looks like I can source an aftermarket stock style for just under $400. Still debating on repair or replace.

Thoughts?

[A6sport]

With that mileage and age, I'd replace it. After all the work you've done, I'd replace both and be done with it.

[f4m0u5]

same thing happend to my a6, broke passanger flange at cat near manifold at 85k miles .....

the thing is these cats are only welded on inside not outside. and eventually give way.


i bought a used cat, then had my shop weld the outside of the flange to make it alot more sturdy, then just had that replace the stock one.(you could also just repair your current one )


im now goingwith testpipes so will have stock cats for sale next month.

[Valpo A7]

The problem I am running in to at the moment is the $400 cats are only available for left side. Right side is sold out which makes me think this broken weld is common. Another Audi fuck up.

Not paying $1200 for an OEM cat.

I may have no choice but to get this welded. Father in law can weld it up, just have to buy some stainless wire for his welder.

[Alabama]

Not paying $1200 for an OEM cat.

Part Number: 4G0254252KX is $940 at Audi Nyack with free shipping, but still as much as an entire aftermarket downpipe. Hopefully you can find something used.

[Valpo A7]

Interesting information when I tried to find used cats to put in it.

It is illegal by federal law to install a used cat which explains why none of the junkyard searches have any cats listed. I am still having no luck in locating a right side cat for a reasonable price unless I want OEM or Magnaflow. The Magnas seem to be an upgraded flow design which means I probably should replace both if I went with them which turns the repairs into a $1400 fix. I was quoted $680 in labor to replace just 1 by an Audi tech that does work outside of his home dealership.

So this weekend coming up I will be tearing the busted cat out of the car and take it to get the flange welded back on. A weekend busting knuckles over paying $2800 to have them done. If the driver side snaps then i will tackle that when it does.

[Valpo A7]

Alright, so I got the broken cat out of the car. Had to lower the tail of the trans to make clearance and take the trans cooler pipe loose. Ran a scope up into the cat to check the cells and while they are not healthy looking it is not clogged. I am really surprised it lasted 206,000 miles and did not break the welds already. Piss poor welding on the factory cat. Almost no weld penetration into the cat pipe, almost all the weld was on the flange. Getting to all 3 nuts on the flange going back in will be interesting to say the least. Seeing the bad welds on the passenger side makes me wonder what shape the driver side is in. For now I am assuming that since it isn’t leaking then I have no problems. Ignorance is truly bliss at times.