weldedhorse

Hello all, new to the forum and sorry if this has been posted, just exhausted! How the heck do I pull my cats out? I have unbolted them unscrewed the sensors...

K04-S4

Do you have 4 cyl with single exhaust or V6 with dual exhaust?

weldedhorse

3.0 v6 dual exhaust

K04-S4

It's not an easy job as the cats are directly behind the heads on the 3.0L. The head to exhaust flange is difficult to access on the 3.0L as it is somewhat recessed into the back of the head and there is very little room to work. Try a mirror and feel your way around.

The O2 sensors you can see when looking straight down between the engine and firewall are the rear O2's. There are another pair of front O2's buried into the exhaust flange recess in the back of the heads that are in front of the cats and they are a bugger to access.

Just out of curiosity, why do you need to remove the cats?

GeneKam

Removing cats will make your ride loud----which is a good thing.

But the downside is...it will smell horrible, im not kidding like absolutely gross. Not kidding it will smell like absolute crap, if you are beside a cop, he WILL pull you over. Its illegal to do because it pollutes the environment.
Drive throughs and idling will become impossible

BUT most of all, you will fail all of your emissions, which you have to do every two years. And installing and reinstalling the cat will become a dread, considering how little room you have to work with.

SUGGESTION... Remove your resonator and put a straight pipe instead, it sounds louder and is pretty damn good.

weldedhorse

I was getting trouble codes for both cats... three different shops said cats are bad its very common with this car;I dont know this is my first audi have only had it since January. I finally removed both cats what a pain. Anyone else reading this "dont do it". It does sound good and I havent noticed a smell yet. I will relocate my cats to a more accesable place in near future.

K04-S4

As Gene indicates, the emissions will be way over spec and the A4 will fail emissions test.

When you say "very common"cat failures on 3.0L car, what is the mileage?

It may be difficult to relocate cats as there is not alot of room downstream. You would have to relocate O2 sensors (wires need extending) and besides you want the cats closest to the heads to heat quick compared to under car relocation.

weldedhorse

I just hit 130,000 miles. I was thinking of relocating them just past the subframe where it opens up a little? On heating up the cat/o2 sensors would two feet really matter? other than extending the wires?

K04-S4

The exhaust smell will make it apparent that there are no cats so anyone driving behind you will know.

What is the issue, your stock cats failed and you want to try using cheaper aftermarket cats or ?

GeneKam

not just that it will be slightly green colored in most cases so its will be apparent to most human senses