Too lean - fault codes

[jakubx80]

Hi there,

2017 S7 stock with 31k miles here.

Within last 1,000 I got the running too lean engine light fault code 3 times.
Each time it was during a low rpm (~1200 rpm) slow moving traffic. The light then goes away on its own after 30 miles or so.

Since the pandemic started I drive roughly 3,000 miles a year and rarely break 60mph if it might have to do with anything.

My car still has CPO warranty. After first engine light I went to Audi and was told that it was a sporadic event and not too worry.

What do you guys think? My previous car was WRX that I put 60k miles on and didn't have a single fault code, so I'm feeling a bit queezy.

Thanks for the feedback.

Sent from my SM-G998U using Tapatalk

[Valpo A7]

Replace the oxygen sensor and reset the code.

What are the Possible Causes of the P2270 Code?

The PCM can get a biased lean signal from the post-catalytic oxygen sensor 2 because of these problems:

Bad or failing oxygen sensor
Exhaust leak
Lean running condition
Corroded or damaged wiring
Failing PCM (rare) or PCM software in need of an update


Take it back to the dealer and tell them about it tripping 3x in the last 1000 miles. Sounds like it has moved on from sporadic. Since its warranty work I am kinda surprised that they don’t want to do the fix since it’s guaranteed payment to them.

[430hps4]

I would normally say stay away from the dealer. But, if you are still under their warranty, milk them for everything they have.

From a DIY perspective, my guess is a small air leak from a vacuum line.

[Alabama]

Take it back to the dealer and tell them about it tripping 3x in the last 1000 miles. Sounds like it has moved on from sporadic. Since its warranty work I am kinda surprised that they don’t want to do the fix since it’s guaranteed payment to them.

Couldn't agree more. That's why you paid extra for the car, to have the CPO warranty. After the dealer replaces the oxygen sensor and everything is good again, for prevention consider using Top Tier gasoline if you're not already, periodic use of a high quality gasoline additive (fuel system cleaner), and occasional fun drives on I-395!