Back to 2000 Audi A6
Help
2000 AUDI A6
2.8L V6•AWD•AUTOMATIC•gas•ACK
4 active safety recalls on this vehicle — view recalls
Founding sponsor spot is openYour name on every procedure for this vehicle, permanently.Sponsor — $99 →
Repairs0Labor503Torque3204Fluid9DTC900Battery1Maintenance0Recalls4
P1105moderate severityPowertrain

HO2S Heater Resistance Bank 1 Sensor 2

on 2000 Audi A6 2.8L V6 · AWD

What this code means

The ECU detected that the heater resistance in the downstream oxygen sensor on Bank 1 is outside the expected range. The downstream sensor monitors catalytic converter efficiency and requires proper heater function.

Symptoms

  • Check Engine Light
  • Failed emissions test
  • Poor catalyst monitoring
  • Slightly reduced fuel economy

Common causes

  • Faulty downstream O2 sensor heater
  • High resistance in heater wiring
  • Corroded connector at sensor
  • Heater relay failure

Diagnostic steps

  1. Test downstream O2 sensor heater resistance
  2. Inspect connector for corrosion
  3. Check heater circuit wiring
  4. Test heater relay operation

Repair notes

Replace the downstream O2 sensor on Bank 1.

🔌 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

🔌 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 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 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 →