P0171 - Fuel Trim, Bank 1 System too Lean

[angrycatmeow]

2018 S5, 50k mi. Got this code about 3 weeks ago, cleared it, and it came back yesterday. Did a search and didn't see any hits on this specific code for B9 S4's and S5's. Looking for suggestions on where to start troubleshooting.

IE stage 1
CTS Turbo inlet
P34 intake
CTS intercooler/charge pipes
TSB 2059446 performed, PCV breather line replaced
https://static.nhtsa.gov/odi/tsbs/20...82173-0001.pdf

Trouble codes:
P017100 - Fuel Trim,Bank1 System too Lean
Intermittent
Date: 2022-11-04 15:57:46
Mileage: 80099 km
Priority: 2
Malfunction frequency counter: 1
Unlearning counter: 255
Engine speed: 835.50 1/min
Normed load value: 10.2 %
Vehicle speed: 0 km/h
Coolant temperature: 86 °C
Intake air temperature: 33 °C
Ambient air pressure: 1010 mbar
Voltage terminal 30: 14.140 V
Dynamic environmental data: 209628107A0311BD0CB83EFC05121605711514041770000137 4110100346

[AudiShport]

2018 S5, 50k mi. Got this code about 3 weeks ago, cleared it, and it came back yesterday. Did a search and didn't see any hits on this specific code for B9 S4's and S5's. Looking for suggestions on where to start troubleshooting.

IE stage 1
CTS Turbo inlet
P34 intake
CTS intercooler/charge pipes
TSB 2059446 performed, PCV breather line replaced
https://static.nhtsa.gov/odi/tsbs/20...82173-0001.pdf

Trouble codes:
P017100 - Fuel Trim,Bank1 System too Lean
Intermittent
Date: 2022-11-04 15:57:46
Mileage: 80099 km
Priority: 2
Malfunction frequency counter: 1
Unlearning counter: 255
Engine speed: 835.50 1/min
Normed load value: 10.2 %
Vehicle speed: 0 km/h
Coolant temperature: 86 °C
Intake air temperature: 33 °C
Ambient air pressure: 1010 mbar
Voltage terminal 30: 14.140 V
Dynamic environmental data: 209628107A0311BD0CB83EFC05121605711514041770000137 4110100346

Hi there. I got this exact code today as well.
2019 S4
IE Stage 1 93
IE FMIC
P34 Intake

I've been noticing rough cold starts the colder the weather.

Did you ever figure this out?
Seems like it could be a lot of things really.

[angrycatmeow]

Hi there. I got this exact code today as well.
2019 S4
IE Stage 1 93
IE FMIC
P34 Intake

I've been noticing rough cold starts the colder the weather.

Did you ever figure this out?
Seems like it could be a lot of things really.

I honestly think it was an early sign of this: https://www.audizine.com/forum/showt...bracket-loose!

You know how these cars don't like electrical gremlins/low batteries. I think when the belt slipped on the alternator it caused an intermittent low voltage, and I would get that code and a couple others for low voltage/implausible signal type stuff. Ever since fixing the alternator issue, it hasn't been back (knock on wood).

I've also noticed some rougher idling in cooler weather until the revs settle down, then it's stable. I haven't heard much about carbon cleaning on these engines, but I assume it's carbon build-up.

[AudiShport]

I honestly think it was an early sign of this: https://www.audizine.com/forum/showt...bracket-loose!

You know how these cars don't like electrical gremlins/low batteries. I think when the belt slipped on the alternator it caused an intermittent low voltage, and I would get that code and a couple others for low voltage/implausible signal type stuff. Ever since fixing the alternator issue, it hasn't been back (knock on wood).

I've also noticed some rougher idling in cooler weather until the revs settle down, then it's stable. I haven't heard much about carbon cleaning on these engines, but I assume it's carbon build-up.

Interesting, mine is not driven much and sometimes I'm lazy to put it on trickle charging so the low voltage would apply here!

And I hope it's not carbon build up I'm only at 18k miles!

Cheers

[angrycatmeow]

Oh well in that case, lets just chalk it up to the tune and move on :) We have very similar mods but my car is at 50k or so.

[LYFESGD]

Just for reference I had the same code as well (IE Stage 1 E85) I solved it by flashing back to stock, then re-flashing back to E85 tune. No codes as of yet...2018 S5 SB 48K mi

[DC3P0]

sorry to revive an old thread but anyone ever get to the bottom of this code? I was on IE Stage 1 - 91 when I got it. I have a FMIC and an intake as well. Flashed back to stock soon after and haven't had any issues since. Been about two weeks.

Just curious if people kept rolling with their IE stage 1 or what else you might have tried.

IE wants me to log it, I'm just not really into trying to make it happen again on their tune. Too much noise out there right now.

[jackmcg12]

sorry to revive an old thread but anyone ever get to the bottom of this code? I was on IE Stage 1 - 91 when I got it. I have a FMIC and an intake as well. Flashed back to stock soon after and haven't had any issues since. Been about two weeks.

Just curious if people kept rolling with their IE stage 1 or what else you might have tried.

IE wants me to log it, I'm just not really into trying to make it happen again on their tune. Too much noise out there right now.

I was seeing the same thing on a 6-month old S4 running IE Stage 1 - 93. Flashed back to stock and having driven some of the same places that it would throw the issue, haven't seen it pop back up.

After some issues I had with their TCU Flash a month ago, mixed with some of these CELs on the B9 platform (compared to rocksolid tune on the B8.5 2.0t platform) I can't bring myself to stick with them while they beta test with all customers cars. Going 034Motorsports now as stock is lacking.

[DC3P0]

I was seeing the same thing on a 6-month old S4 running IE Stage 1 - 93. Flashed back to stock and having driven some of the same places that it would throw the issue, haven't seen it pop back up.

After some issues I had with their TCU Flash a month ago, mixed with some of these CELs on the B9 platform (compared to rocksolid tune on the B8.5 2.0t platform) I can't bring myself to stick with them while they beta test with all customers cars. Going 034Motorsports now as stock is lacking.

Yeah I tried recreating the conditions on stock for almost a month. Logged a ton. No CELs, nothing out of whack. Took advantage of the 034 competitor switch discount which made it slightly easier to stomach paying for two tunes.