Removing Passenger Catalytic Converter (Failed) - 2014 B8.5 S4 (pictures for views)

[Antekaudi]

Hi Everyone,

It appears that my OEM catalytic converter on the passenger side had snapped at the flange.

Is it possible to replace the cat without dropping the engine or removing the transmission ?

Car is 2014 B8.5 S4 6MT 25k Miles with AWE Exhaust Non Res with EPL stage 1 tune.

Anyone had similar issue in the past ?

Thanks

[B18b1ex]

Your car should be under warranty, why did it snap? If not your doing why not have the dealer fix this? Isn't flashing at home by EPL not it's main selling point?

[Antekaudi]

The car will be fixed under warranty through the dealer i have purchased the car from. However, I would like to know if there is an easier way to get to the cat other than dropping the drivetrain.

I am not sure why it snapped but i have found couple other people with same problem.

Thanks

[Vogz]

The car will be fixed under warranty through the dealer i have purchased the car from. However, I would like to know if there is an easier way to get to the cat other than dropping the drivetrain.

I am not sure why it snapped but i have found couple other people with same problem.

Thanks

99% sure you have to remove the trans.


EDIT: Apparently some people have swapped cats without pulling the trans, but after doing an trans R&I on my own car, I really can't see how this is possible.

[F16HTON]

You do not have to remove the transmission, cat replacement is a fairly simple job, you just need the right tools and a tech that has some experience.

[Antekaudi]

Interesting, any more details on how can this be done without removing transmission ?

Thanks

[sonic32]

The car will be fixed under warranty through the dealer i have purchased the car from. However, I would like to know if there is an easier way to get to the cat other than dropping the drivetrain.

I am not sure why it snapped but i have found couple other people with same problem.

Thanks

I'm one of them. The flange snapped clean off the header on passenger side, had my guy pull it out and gave it a nice weld around


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[sonic32]

Interesting, any more details on how can this be done without removing transmission ?

Thanks

Lower subframe and wiggle it out, I'm pretty sure that's what he told me he did


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[rtl5009]

You have to lower the subframe and let the trans sag and it'll wiggle out with some finesse. It's a complete pain in the ass.

[Antekaudi]

Thanks. I will have them try that, worst case drop the whole drivetrain.

[Antekaudi]

Car is all fixed.

Had to take out the transmission to get to it.

Here is the catalytic convert failure:

[rtl5009]

The flange broke off?!? I hope you did a clutch too if the shop "had to" take the trans out (which you don't cause I have done it twice myself)

[Vogz]

The flange broke off?!?

That's how a lot of these have been failing lately. Crazy.

[MerkurRS]

YES!!!

I broke mine on the 3rd run at the track (after two previous horribly slow runs at 12.01 in the quarter).

I spoke to several Audi tuners/ mechanics and no one has "heard" of these breaking. I am glad to see I didn't break something that no one has ever broken before. I ended up welding up myself. Not my best welding, but I began to remove the cat at 5:00 PM (after work) and had it installed and running by 4:00 AM.

[rtl5009]

That's a straight manufactures welding defect. HAZ was too shallow. Nice job getting it to line up!

[rtl5009]

Do you guys have your dp spring hangers hooked up properly to your exhaust and trans case?

[sonic32]

Mine sheared off exactly the same. Had the same issue, but my guy got it out without dropping the tranny. He did my clutch a few months prior to that


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[SteveYem]

What symptom(s) occur when this happens? CEL, loud noise, both?

[Szemenyei]

That happened to me the dealer repaired it under warranty because its an emissions part.

[rtl5009]

Federal law covers cats to 80k mi/ 8years.

[rtl5009]

It's seems awe exhaust are a common theme with this failure. They are also really popular so it could be correlated but non-causal.

[Antekaudi]

Hangers, spring loaded bracket and the exhaust are properly installed. We could probably get to the driver side cat without removing the transmission but on the passenger side with the manual and differential in the way it was way too tight.

The shop has seen couple failures like that on other models such as stock Audi A7.

I wonder if having AWE or any aftermarket exhaust makes this issue appear quicker.

Thanks

[sonic32]

I have stock exhaust and mine failed the same way so I don't think it had anything to do with the exhaust. It's just a lot
Of back pressure on that side. I was also running a lot of E85 at that time on the race map so that probably accelerated the failure


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[AKPS4]

I am another victim of this. Passenger side flange broke off clean. Absolutely a manufacturing issue. Didn't bother with dealer because of all my mods. But after having it fixed I found I have loose and missing bolts at the DP to cat connection.

I am looking for a DIY to drop the subframe to reach these bolts. Anyone have anything. Nothing available after searching.

[sonic32]

I am another victim of this. Passenger side flange broke off clean. Absolutely a manufacturing issue. Didn't bother with dealer because of all my mods. But after having it fixed I found I have loose and missing bolts at the DP to cat connection.

I am looking for a DIY to drop the subframe to reach these bolts. Anyone have anything. Nothing available after searching.

Passenger side broke off clean on mine too, I have a funny video from my mechanic that I don't know how to attach of him spinning the flange on the cat pipe and it's spinning by itself lol


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[KnewJack]

Had a similar failure. Passenger side separated at the weld on the cat itself. Replaced under warranty. Now I think my drivers side cat is slowly gutting itself. Exhaust has taken on a slightly deeper and more raspy tone.

[jl87]

Gutted a set on an S5 yesterday. Dropped a little over 2lbs of catalyst material from each one. They weighed 9lbs 6.4oz before starting, car was stage 2 going to ultra, but they didn't look to be in terrible shape.

[jachien]

I am another victim of this. Passenger side flange broke off clean. Absolutely a manufacturing issue. Didn't bother with dealer because of all my mods. But after having it fixed I found I have loose and missing bolts at the DP to cat connection.

I am looking for a DIY to drop the subframe to reach these bolts. Anyone have anything. Nothing available after searching.

not exactly a DIY but process is similar, but try and follow 034 Motorsports install guide for their replacement motor mounts.

https://store.034motorsport.com/blog...s4-a5s5-q5sq5/

[AKPS4]

Thanks this is helpful. Doesn't sound like anyone has attempted a cat replacement themselves so not finding any info on if subframe just needs to be lowered or if completely removed.

Anyone have access to a factory manual for full procedure ?

[jl87]

Only have to lower it, also dip the back end of the trans. That's how we did it 2 days ago. Removed the false firewall to get access to the top bolts, then lowered subframe, disconnected axles/shields, remove downpipes, and then finagle them out.

[jwye120]

not exactly a DIY but process is similar, but try and follow 034 Motorsports install guide for their replacement motor mounts.

https://store.034motorsport.com/blog...s4-a5s5-q5sq5/

Thanks for this info. I've been searching for anything I could get on the easiest way to get the cats on my b8.5. Plenty of people respond to the question but much like this thread it's not until the 28th or higher post that someone offers some real information. Instead you get a plethora of people with 5th hand information they learned from reading other posts but have no real world experience. Sorry for the rant, its just getting really frustrating having to sift through so many posts without useful information attempting to answer questions that weren't asked. It's almost like people just want to see their name on the message board.

I'm not referring to the people posting about their actual experience. More the people saying it's super hard don't bother attempting yourself, or actually its fairly simple you just do blah blah blah.

[jachien]

Thanks for this info. I've been searching for anything I could get on the easiest way to get the cats on my b8.5. Plenty of people respond to the question but much like this thread it's not until the 28th or higher post that someone offers some real information. Instead you get a plethora of people with 5th hand information they learned from reading other posts but have no real world experience. Sorry for the rant, its just getting really frustrating having to sift through so many posts without useful information attempting to answer questions that weren't asked. It's almost like people just want to see their name on the message board.

I'm not referring to the people posting about their actual experience. More the people saying it's super hard don't bother attempting yourself, or actually its fairly simple you just do blah blah blah.

There was a thread for some Mertop Chinese headers somewhere. I documented it as much as i could for diy’ers to be able to follow. Hope it helps.

Edit: found it for you

https://www.audizine.com/forum/showt...4#post12586664

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[jwye120]

There was a thread for some Mertop Chinese headers somewhere. I documented it as much as i could for diy’ers to be able to follow. Hope it helps.

Edit: found it for you

https://www.audizine.com/forum/showt...4#post12586664

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The link you already posted was exactly what I was looking for. I was ranting because your post was #28 and pretty much the first post that actually responded to the original posters' question. I'll check that other thread out though, thanks again.

[jachien]

The link you already posted was exactly what I was looking for. I was ranting because your post was #28 and pretty much the first post that actually responded to the original posters' question. I'll check that other thread out though, thanks again.

Lol a lot of side commentary that’s for sure. Not just here but in other threads as well. I think the link i just provided you is a bit more specific on removing the cat, unless you plan on dropping the engine completely. Pretty much though, the subframe needs to be dropped a lot in order to squeeze the passenger side cat out without dropping the engine/transmission.


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[DankFX]

My car is in the shop for this same problem, I was told they would need to take out the trans.. I did find this video showing that you might not need to but, they don't show themselves removing the cat, so not sure how "easy" it is.

https://www.youtube.com/watch?v=eXuP7ZBkkVs

[RodrigoJacobo]

Hey there I know this post is old, however, I'm wondering how long those welded cats lasted? Will it be ok to weld them back on, noting I'm getting CTS turbo motor mounts?

[RodrigoJacobo]

YES!!!

I broke mine on the 3rd run at the track (after two previous horribly slow runs at 12.01 in the quarter).

I spoke to several Audi tuners/ mechanics and no one has "heard" of these breaking. I am glad to see I didn't break something that no one has ever broken before. I ended up welding up myself. Not my best welding, but I began to remove the cat at 5:00 PM (after work) and had it installed and running by 4:00 AM.

Hey I know this is an old Post Just wondering if those welded cats lasted, Mine snapped of aswell. I'm assuming all the vibration from my failed mounts caused them to snap, would you recommend welding it back on.