Back to 2000-2003 Audi S6
Help
2000-2003 AUDI S6
4.2L V8•AWD•AUTOMATIC•gas
2 active safety recalls on this vehicle — view recalls
Founding sponsor spot is openYour name on every procedure for this vehicle, permanently.Sponsor — $99 →
Repairs0Labor550Torque3386Fluid6DTC718Battery1Maintenance0Recalls2
P1128moderate severityPowertrain

Long Term Fuel Trim System Too Lean Bank 1

on 2000-2003 Audi S6 4.2L V8 · 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.
As an Amazon Associate, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.

Other Powertrain codes on this vehicle

🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota 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 2000-2003 Audi S6 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 S6 — $99 →
Building an app?
Free API access to all this data — 50 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 →