Back to 2019 Audi A6
Help
2019 AUDI A6
2.0L Turbo I4•AWD•AUTOMATIC•gas•CYRB•turbo
7 active safety recalls on this vehicle — view recalls
Founding sponsor spot is openYour name on every procedure for this vehicle, permanently.Sponsor — $99 →
Repairs0Labor495Torque5248Fluid8DTC1145Battery1Maintenance0Recalls7
P1128moderate severityPowertrain

Long Term Fuel Trim System Too Lean Bank 1

on 2019 Audi A6 2.0L Turbo I4 · AWD

What this code means

The ECU detected that the long-term fuel trim for Bank 1 has reached the maximum lean correction limit. The engine is not receiving enough fuel relative to the air charge, and the system cannot add more fuel.

Symptoms

  • Check Engine Light
  • Rough idle
  • Hesitation on acceleration
  • Lean misfire
  • Poor fuel economy

Common causes

  • Vacuum leak on intake side
  • Weak fuel pump
  • Clogged fuel injectors
  • MAF sensor under-reading
  • Intake manifold gasket leak

Diagnostic steps

  1. Perform smoke test for vacuum leaks
  2. Monitor fuel trim values
  3. Test fuel pressure
  4. Clean or test MAF sensor
  5. Inspect intake manifold gasket

Repair notes

Repair vacuum leaks first; then address fuel delivery issues if trims remain lean.

🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITE
Shop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.

Other Powertrain codes on this vehicle

🔌 Need this data in your app? It's all in the free API →
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Mechanic · 20+ years. Spot an error? Use the Help link above — a human reads every report.
Stuck on this repair? Take it to The Diag Desk — ask a master tech about this exact car → real human answer within 24h, never AI
Share:XRedditFBWhatsAppThreadsEmail
⚠ STILL BEHIND THE PAYWALL
The 2019 Audi A6 repair data is incomplete because no one has sponsored it yet. For $99, we generate the full step-by-step procedures, then fact-check them with a second AI pass and your expert review. Your name on every procedure, permanently.
The same data would cost $169/mo from Mitchell1 or $30/year from ALLDATAdiy — and you'd be renting access, not freeing it. Sponsor once, free forever.
Sponsor the Audi A6 — $99 →
Building an app?
Free API access to all this data — 10 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →