Any experience with cheap catalysts?

[davidvia]

Hello All! (I posted also this to the C7 forum on AudiWorld. Apologies for the redundancy for any “dual citizens” - I didn’t know which community was more active/engaged…)

I’m trying to economically extend the life of our 2014 A6 2.0T Quattro with the CAED motor. We’re just over 130k and have been in the typical heavy oil consumption mode roughly since we turned 100k - averaging a quart every 900 miles since then.

Recently threw a P0420 (“Efficiency Below Threshold”) code which I was able to download and clear with VCDS and it has stayed off for about a week now. My long-time trusted indy mechanic is pretty certain that the catalytic converter is on it’s way out due to 30K of burnt oil exhaust now clogging up the cells.

I am not interested in spending $$$ on a replacement cat for this vehicle. The car in great shape, but it’s just not worth it knowing that the oil consumption will continue to get worse until the engine finally fails and then I will end up junking it. (I’ve already ruled out the $$$$ of an engine rebuild or replacement. Working my way through various non-rebuild treatement options...)

So…has anyone here had any experience with the low cost Chinese-made replacement catalytic converters that are out there for our 2.0T motors? Like this for example:

https://www.ebay.com/itm/335773938566

The cost difference is mind-blowing. I have always avoided low-cost knock-off parts, and bought OEM or equivalent - but a 90% difference in price is just too big of a temptation for me to ignore in this case…

Thanks in advance for any wisdom the community has to offer!!

[Valpo A7]

For what its worth in terms of the 3.0. I have no idea about the first owner but we bought at 142K miles on a 2012 A7. From the day we bought it it has always consumed oil and seen the tell tail exhaust puffing many times. I put another 90,000 miles on it and traded it at 234,000 miles with the original cats. I know the first owner never replaced the cats as he always went to the dealer for repairs and I had a copy of all the service on the car and no where does it say new cats got installed.

You might try a product called CATACLEAN and run that through and look at replacing the O2 sensors first before shelling out the money and labor for new cats.


as for aftermarkets, I know rock auto sells a crap ton of aftermarket for the Audi platform. At some point I broke the flange off on my passenger side cat and first looked at RA but they were sold out. As quick as new ones arrived they went back out in sales.

[davidvia]

Thanks for that! I will look into CATACLEAN! (Lord knows I am looking at/trying all kind of other chemical remedies to try to free up my piston rings and lower my oil consumption! 😊)

Interestingly, RA does not list a cat at all for my A6, which I thought was pretty weird. Autozone and O’Reilly both offer the Magnaflow 52292 that looks like / claims to be direct fit for $800.

Way better than the Audi part, but still 4x the cost of the Sarotin on Ebay.

[STXA7]

big question is are you in a county that requires emissions testing....?
in my experience, labor cost more than the most expensive aftermarket catalytic converter or test pipe with 3.0t maybe your luck is better on the 2.0t.
your cheapest option might be to have the cat straight piped. i can't find any aftermarket options for a6 , only other vw/audi model with your engine.

i've seen people on youtube soak their factory cats of other trucks cars etc. in water / various common solvents cleaners etc. who knows it might remove the burnt oil residue but wont bring back lost catalytic precious metals or resolve cracking

if you need to pass the plugin type emissions / tailpipe testing you will need a cat that is as efficient as OEM , high flow seem to be 200cel for your engine in other platform cars.... maybe go for a 300cel universal from a reputable source, maybe even an OEM takeoff cat from another EA888 car

[davidvia]

We do have emission testing in my county - but there is no longer a visual inspection - so all I have to do to get paper is make the OBD say the magic words. 😊

I was considering a test pipe with a downstream O2 sensor spacer, but wasn't able to find anything ready-made for the EA888 in the A6 application either.

The 2.0T doesn’t seem to have been a very popular choice for C7 buyers.

[STXA7]

We do have emission testing in my county - but there is no longer a visual inspection - so all I have to do to get paper is make the OBD say the magic words. [emoji4]

I was considering a test pipe with a downstream O2 sensor spacer, but wasn't able to find anything ready-made for the EA888 in the A6 application either.

The 2.0T doesn’t seem to have been a very popular choice for C7 buyers.

No visual inspection means your chosen solution doesn’t have to be pretty ( pretty welds cost more ).

There’s a thread in the B8 s4 section about blown catalytic converters. A recent post from someone says they had their engine blow from excessive back pressure caused by failed cheap replacement cats.

A spacer might work well enough to fool the emissions test, but you might want to remove it after since the ECU needs accurate measurements for daily driving fuel air ratio.


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[MyDimeIsUp]

A P0420 always means your cats are bad. If its a problem with the O2 sensors (P0150 - P0165 if I recall), you would get a separate code. People don't like to acknowledge that $1,000+ cats need to be replaced. I would not buy a cheap eBay cat. Possible issues with backpressure, and moreso how the heck are they sourcing enough of those precious metals to burn off harmful exhaust chemicals, putting it into a pipe and selling for $192?

The 2.0T I think RedStar or whatever was a reputable brand, but honestly I'd find a used low-mileage cat and do an engine rebuild with new pistons if you can do the work yourself. The 2.0T is easy to rip out of the B8 platform. Since the C7 has much more room, it should be even easier to just disconnect the tranny and lift it out the front. Easy engine to work on too, especially when the engine is out of the car. When I had my B8 allroad 2.0T, I had Kolbenschmidt (OE) pistons priced with all new nuts, bolts, gaskets, etc. and it came to about $1,400 - $1,800, but that doesn't include about $500 in timing parts since I had previously done that 2 summers prior. So all in for $3,000, you can have a car that doesn't burn any oil (and has the updated piston rings so oil burning won't be a problem in the future) and good-condition cats that haven't already been clogged nor will clog in the future due to new pistons. Engine should last you easily another 100k with new pistons, timing, etc.

Just my $0.02, though again all of those hinges on the fact you can do the work yourself. An O2 spacer would be enough to fool the self-test to pass so you can pass emissions, but eventually with that excessive of oil burning there are stories of burnt exhaust valves. Unfortunately (or fortunately depending on how you look at it) my allroad was t-boned 3 months before I was ready to rip the engine out of it. Still miss that car despite the oil burning.