P0420 CEL code help

[2wookies]

Got the dreaded Catalyst system bank 1 efficiency below threshold. Stage 1 APR tuned A7 with AWE exhaust. What are my options here? Spoke to the dealer on the phone, super cool guys here in Omaha, and he thinks my tune smoked the cat. I’m out of warranty....so has anybody else had this issue??

[Dutch_A6]

I've had it, I just keep clearing it with my Ross tech, only pops up about once a month. I'm stage 1 EPL, only thing you can really do is get new cats from what I've found out.

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[ryanlada]

I've had it, I just keep clearing it with my Ross tech, only pops up about once a month. I'm stage 1 EPL, only thing you can really do is get new cats from what I've found out.

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Deleted.
Missed that you were talking about an A7.

[Mscarn2014]

Got that within a month of buying my 2014 A6 with 68k miles last year.

Long story short, eventually got O2 spacers for the cat, along with carbon cleaning and haven't gotten the code back since.

[VVG]

Got the dreaded Catalyst system bank 1 efficiency below threshold. Stage 1 APR tuned A7 with AWE exhaust. What are my options here? Spoke to the dealer on the phone, super cool guys here in Omaha, and he thinks my tune smoked the cat. I’m out of warranty....so has anybody else had this issue??

It has been said before and it will be sad again....gotta pay to play. Not sure how long you have been tuned, but over time, running more boost and fuel and generating more stress and heat will cause parts to wear faster. Easiest solution is to get new cats. If you are committed to still keeping the car for a while, you could even just go to Stage 2 with new downpipes. APR if there are no emissions testing concerns, or AMS if there are.

My 2014 S6 now has a little over 60,000 miles. The car is my daily driver so I need it to be reliable. I had an APR tune on the car from about a little over 3000 miles (once I knew there were no major engine flaws) to a little over 50,000 miles. I then removed my ECU and TCU tunes and went back to stock. I don't need the hassle of dealing with parts breaking. And make no mistake, tuning your engine will cause faster engine wear and significantly more heat stress on all the parts in the engine bay. I will be getting a new car next year, so I also want to minimize my risk of a potentially costly repair just before buying a new car. I thoroughly enjoyed the benefits of the tunes, but as my car ages, it makes the added stress more risky.

So.....If you are out of warranty, I would really start thinking about how long you want to keep the car and what you are willing to spend on the up keep, which is going to be more if you car is tuned. Or, you may want to considering just going back to stock and riding out the rest of your ownership lifespan that way until the next car if it isn't too far away.

[Mscarn2014]

Ive been told by many that the cats are usually ok, but the software is very strict and will throw the code because the threshold is actually really low. What year is your car? Dealer told me my ECU/firmware was really old and an update from them might actually fix it.

Instead I went to an independent mech to get stage 2, he also installed O2 spacers on the cats. Haven't seen the code since.