Hi all,

I recently picked up a very tidy 2012 S4 and I've been working towards a stage 2+ tune. As I wait for parts to arrive, I've been considering what to do with the factory cats.

From the reading I've done, it seems the liklihood of melting the cats increases once you hit stage 2 and obviously I'd like to avoid any issues.

I like the idea of high flow cats, the 034 ones aren't crazy expensive, but seem to only be made for left hand drive cars.

Then there's test/down pipes or gutting the cats but I don't really want to make the car any louder. Plus parts are bloody hard to come by down this end of the world.. the cheapest test pipes I can find are around $1500.

Are there any other options I should consider? I know removing the factory cats is going to be a mission so I'm hoping to keep it as simple (and WOF friendly) as possible.

TIA for any help.

Gut your existing cats - and then reinforce the flange welds to make sure they don't crack under the heat.

Replace the baby resonators by the trans with some GESi hi flow cats. This allows you to remain legal, with no smell, no test pipe rasp. Plus cats still work that far back.