P0137 means the downstream oxygen sensor on Bank 1 (post-catalyst, Sensor 2) is reporting a voltage that stays too low for too long. This typically indicates a lean exhaust condition reaching the sensor, an exhaust leak ahead of the sensor, or a failed sensor stuck at low voltage. The downstream sensor should read a relatively steady 0.6–0.8V when the catalytic converter is working properly.
DTC/P0137·Audi
P0137 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)Audi
P0137 on a Audi means the downstream oxygen sensor on Bank 1 (post-catalyst, Sensor 2) is reporting a voltage that stays too low for too long. This typically indicates a lean exhaust condition reaching the sensor, an exhaust leak ahead of the sensor, or a failed sensor stuck at low voltage. The downstream sensor should read a relatively steady 0.6–0.8V when the catalytic converter is working properly.
Repair cost on Audi€56 - €388
What does P0137 mean on a Audi?
Audi A4
2006–2024The B7 and B8 A4 with 2.0 TFSI shares the EA113/EA888 oil consumption issue plus carbon buildup on the intake valves. Both contaminate the downstream sensor over time. Walnut blast the intake before condemning the sensor on any TFSI over 80,000 km. The downstream connector lives in a tight spot near the gearbox bellhousing.
What causes P0137 on a Audi?
Beyond the generic causes listed on the main P0137 page, these are the Audi-specific patterns we see most often:
Audi A4Carbon buildup on 2.0 TFSI affecting combustion stability and sensor signal
Audi A4Connector access difficulty leading to incomplete reseating after work
How to diagnose P0137 on a Audi with OBD2
Follow these steps to pinpoint the root cause of P0137:
- Read freeze frame data and check for any companion codes (P0420, P0171, P0174) that suggest a lean condition or converter problem
- Inspect the exhaust system between the catalytic converter and the downstream sensor for cracks, loose clamps, or leaking gaskets
- Inspect the Bank 1 Sensor 2 connector and wiring for corrosion, heat damage, or chafing
- Use a scan tool to view downstream sensor voltage. A healthy sensor reads around 0.6–0.8V steady. A reading stuck below 0.2V points to sensor failure or an exhaust leak
- Substitute a known-good sensor or swap with the Bank 2 downstream sensor if equipped. If the low voltage follows the sensor, the sensor is faulty
How much does P0137 cost to fix on a Audi? (EUR)
Estimated repair costs on a Audi (Audi parts and labour typically run 25% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0137 on Audi
These codes commonly cluster with P0137 on Audi vehicles:
FAQ: P0137 on Audi
Can I drive with P0137?
Yes, for short distances. The downstream sensor does not directly control fuel injection, so the car will run normally. Long term, the low signal often masks a developing exhaust leak or converter issue that should be addressed.
Can an exhaust leak cause P0137?
Yes. Even a small leak between the catalytic converter and the downstream sensor lets fresh air reach the sensor, which it reads as a lean exhaust and reports as low voltage. Check for cracked welds, loose clamps, and worn gaskets before replacing the sensor.
Will a bad O2 sensor damage the catalytic converter?
Not the downstream sensor by itself. P0137 alone does not change fuel mixture significantly. But if the underlying cause is a real lean condition or a failing upstream sensor, that can damage the converter over time.
How much does it cost to fix P0137 in Europe?
Replacing the downstream sensor at an independent garage typically costs 100–250 euros total. Dealership pricing runs 200–400 euros, mostly due to OEM-branded sensors versus identical Bosch or NTK aftermarket units.
Looking for the full P0137 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0137 guideSkanyx · Audi
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