2012 A7 CAT starting to fail

[Z3R013]

Hey Guys,
I have been getting a CEL that is saying my CAT’s are starting to fail. I thought, okay I will straight pipe it (I know it’s illegal,bad for environment, etc.) but it is the easiest/cheapest fix.
BUT… then I wouldn’t be able to get a tune for it.
What are my options??

Current mods: APR tune, APR cool air intake, upgraded pulley, supercharger, full APR exhaust.



Sent from my iPhone using Audizine

[Z3R013]

IMG_6156.JPGIMG_6158.JPG


Sent from my iPhone using Audizine

[Valpo A7]

Some have done test pipes that still have the O2 sensor after the cat location. Might need spacers for that. The issue is going to be getting a shop to do the work unless you turn your own wrenches. Many shops will not remove the cats to install test pipes as they are legally on the hook for the work.

[Z3R013]

Test pipes? I have never heard of that. Do you happen to have link to what I can order?

My brother has a lift and I will be doing the work myself


Sent from my iPhone using Audizine

[Alabama]

Test pipes? I have never heard of that. Do you happen to have link to what I can order?

My brother has a lift and I will be doing the work myself

Don't know a source, but here's a definition from Vivid Racing (they don't seem to have test pipes for a 2012 A7):

What are Test Pipes for?

Warning: It would be a good place to start by saying that test pipes aren’t legal for road use. If you drive around town with these and get apprehended, you can’t say we didn’t warn you.

Now we got that over, what is this test pipe thing?

Catalytic converters are standard for most vehicles in most states. It is one of, if not the, most important parts of a car to make battle with ever stringent emissions standards. Cat-converters turn hazardous toxins into harmless gases.

However, because factory catalytic converters make nice with emissions standards, it causes some backpressure which limits your engine to produce more horsepower thus, hindering performance.

Installing a test pipe might just be a sound solution.

A test pipe is the section of piping in an exhaust where the catalytic converter is. Removing the catalytic converter creates much higher exhaust flow. For turbocharged cars, this results in less back pressure and better flow for the turbine.

Test pipes or, cat delete pipes, or straight pipes, do not contain a catalytic converter. The performance of your vehicle greatly increases with the introduction of a cat test pipe to the exhaust system. A test pipe is essentially just a piece of tubing with the correct flanges welded on to be a direct replacement for a catalytic converter.

Whereas the catalytic converter changes your vehicle’s exhaust toxins into harmless gases, a test pipe allows the pollutants to flow straight out of the tailpipe. The most common reason for installing a test pipe is because the cats can be a large restriction in a car’s exhaust system and removing it can free up noticeable amounts of power and performance.

[Valpo A7]

Test pipe example:

https://jhmotorsports.com/exhaust-ra...7-a7-3-0t.html

[Z3R013]

Thanks for the responses! So test pipers are just straight pipes. I can cut out the CAT and put a sec onto on of pipe on with couplings but…
My tune would be screwed up then. Any ideas?


Sent from my iPhone using Audizine

[S5boxster]

Thanks for the responses! So test pipers are just straight pipes. I can cut out the CAT and put a sec onto on of pipe on with couplings but…
My tune would be screwed up then. Any ideas?


Sent from my iPhone using Audizine

Hey, 034motorsport has a tune for test pipes, with cats, and email them about you wanting to switch from apr they will give u a discount. I have b8.5 s5. With 3.0 supercharged engine dual pulley stage 2+ they have been pushing r&d on the 3.0 engine way more than apr
You can get test pipes or u can get headers,
Headers Will mount to the exhaust manifold and will connect to downpipes, test pipes are cheaper.
I was only suggesting headers as ur brother had a lift.
If U plan on keeping the car long term, I would suggest headers, if uncertain and to save $$ test pipes.


https://mertopracing.com/product/mer...rcharger-2009/

IMG_1311.jpg
IMG_1312.jpg

[Valpo A7]

Are you for sure that the cats are failing and its not really a problem with the Oxygen sensors?

[Alabama]

Are you for sure that the cats are failing and its not really a problem with the Oxygen sensors?

You're too smart! Would a VCDS type scan identify this problem?

[Valpo A7]

These are common problems of a bad CAT.

- Sulfur smell
- Large fuel economy decrease
- Failed emissions test
- Check engine light
- Discolored or warped outer housing
- Noticeable lack of acceleration
- Hard starting or no-start condition


If these problems are not present then it may not actually be the CAT but rather another component in the car. Unfortunately there are several of these symptoms that point to a bad O2 sensor as well. There are specific testing procedures to check the health of an O2 sensor, I would test them before loading up the parts cannon with expensive labor intensive parts. Typically a CAT converter is fairly robust and should last a very long time. Mine are original at 220,000 miles but I am also completely stock. I have been driving and wrenching since the 1980s and have only changed 1 cat converter.

Depending on the tune, they are not particularly CAT friendly especially crackle tunes; but stock should last a long time.

Bosch O2 sensors should be available for under $100 and take maybe an hour each at most to change out. Converter labor outside the dealer could be $1,000 each plus the converter will run you $500 to $1500 each.

Test test test test, THEN load the parts cannon.

[jrsAudiA6]

Hey Guys,
I have been getting a CEL that is saying my CAT’s are starting to fail. I thought, okay I will straight pipe it (I know it’s illegal,bad for environment, etc.) but it is the easiest/cheapest fix.
BUT… then I wouldn’t be able to get a tune for it.
What are my options??

Current mods: APR tune, APR cool air intake, upgraded pulley, supercharger, full APR exhaust.



Sent from my iPhone using Audizine

I recently had to replace the cats on MY12 A6. In my case the cat on the passenger side broke at the flange connecting to the header. You check out my sig for the mods on the car. The indy shop I used suggested replacing both since it was probably going to need replacement in the near future anyway. As Valpo A7 indicated you need to make sure that the cat(s) are the real issue. Each cat cost me $2300 from the dealer and there is no direct replacement available in the after market yet. Since you are in Oregon your smog rules may be more lenient the CA and you might be able a much cheaper CAT that can be to fit a competent shop. If you have VCDS or know someone that has it scan the codes and report back, perhaps the codes will lead to a more precise diagnosis.

P.S. It turned out when inspecting the driver side cat on my car it was showing signs of melting, so I happy with the decision I made to replace both.

[Valpo A7]

While I say my CATs are original I must add that my passenger side broke off at the flange as well. Internally it looked good so I had my father in law weld the flange back on. The factory weld for the flange was done pretty badly and it got very little little penetration into both the pipe and flange which seems to be the root cause of the failure. I did not inspect my driver side.

The part that really sucks is I had the engine out of the car about 2,000 miles or so before the flange broke when I was doing the timing chains. Had I known then about the potential problem I probably would have had them both re-welded.

[f4m0u5]

magnaflow has direct fit cats for sale. they are oem grade not high performance tho.

https://www.magnaflow.com/collection...tic-converters

[jrsAudiA6]

magnaflow has direct fit cats for sale. they are oem grade not high performance tho.

https://www.magnaflow.com/collection...tic-converters

They do but AFIK they are still not available for sale but hopefully some day because the price I have seen for them is less than half what I paid for the OEM cats.

[Liberty0rDe4th]

Not sure how different the Cat from a 2007 A4 Quattro is. I have one that has been sitting on my garage floor for a year. Car only had 45k on it when I pulled it for a HF cat. Why not buy an aftermarket HF cat? Mine was only about 400$.

Sent from my Pixel 6 Pro using Audizine Forum mobile app

[Valpo A7]

As of right now the Magnaflow site says IN STOCK for both.


Are you gonna do the work or pay for labor? I have done the passenger side but not the driver side. Passenger side is not terrible but access is lousy which is the compounding factor. The factory manual mentions taking the steering apart to get the cat out and back in.

[Liberty0rDe4th]

As of right now the Magnaflow site says IN STOCK for both.


Are you gonna do the work or pay for labor? I have done the passenger side but not the driver side. Passenger side is not terrible but access is lousy which is the compounding factor. The factory manual mentions taking the steering apart to get the cat out and back in.

Ouch!!

Sent from my Pixel 6 Pro using Audizine Forum mobile app

[Z3R013]

Thinking about going straight piping but with these. Image1653696363.627039.jpg


Sent from my iPhone using Audizine

[bahula03]

If there are still those As Seen on TV stores around, they've got a pile of those things sitting around gathering dust.

There's plenty of good advice in this thread, including actually diagnosing the problem so you aren't throwing parts at it and hoping for the best. I haven't seen the mileage mentioned, but a MY12 car that's seen normal use would be prime for O2 sensor failures. If your heart is set on replacing the cats, there are two options: get test/straight pipes and change your tune like S5boxster mentioned, or get new cats, whether OE or aftermarket. Probably worth noting that with the 3.0t, test pipes gain next to nothing performance-wise.

[Thomas@TAI-VW]

I have installed "test pipes" on S4's before,and if you do it to your A7,you will turn your nice,luxury German barge into a boy racer Mustang. They sound HORRIBLE. It sounds just like a V6 Mustang with the diarrhea exhaust .......if that is what you like,then enjoy. It really cheapens the car and limits the audience that will buy it if you choose to sell one day. If you want the ricey sound of fart cans....just get a little rice mobile or Mustang.

[Audibellybutton]

bro just gut the cats and run o2 spacers with a tune. you'll pass