OBD codes / P0150
P0150
ModerateO2 Sensor Circuit Malfunction (Bank 2, Sensor 1)
Driving short-term with P0150 is fine — the computer runs Bank 2 on fallback fuel values, so the engine stays drivable at the cost of some economy. Do not let it linger for months: sloppy fuel control on one bank feeds that bank's catalytic converter a worse mixture than it was designed for.
What this code means
P0150 is the general circuit fault for the upstream oxygen sensor on Bank 2 — the cylinder bank opposite the one containing cylinder 1, which means this code appears only on V-type, flat, or other split-bank engines (an inline four-cylinder has no Bank 2). Sensor 1 sits before the catalytic converter and feeds the computer the rich/lean signal it uses to trim fuel on that bank, so an unusable signal here degrades fuel control for half the engine. The code sets when the sensor's output is out of range, erratic, or otherwise not believable. A worn-out sensor leads the causes, followed by wiring or connector faults and exhaust leaks near the sensor. On some transverse V6 installations the Bank 2 upstream sensor is the hardest of all four-plus sensors to reach, which affects the labor side of the repair.
Symptoms you might notice
- Check-engine light
- Reduced fuel economy
- Rough idle or light hesitation
- Failed emissions test
What it costs to fix
Typical range: $150–$600 · about ~0.3–1.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Upstream oxygen (O2) sensor | $50–$250 | ~0.3–1.5 hrs |
| Wiring / connector repair | $10–$120 | ~0.5–1.5 hrs |
| Exhaust leak repair near the sensor | $20–$200 | ~0.5–2 hrs |
The part cost matches any upstream sensor; the wildcard is access. On transverse V6 engines Bank 2 often faces the firewall, and reaching its upstream sensor can add real labor compared with the same job on Bank 1.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0150 for my exact vehicle →
Frequently asked
What is Bank 2, and does my car have one?
Bank 2 is the cylinder bank opposite cylinder 1 — it exists only on V-type, flat, and similar split-bank engines. Inline fours have a single bank, so they can never set P0150; if you have this code, you have a V6, V8, flat, or similar engine.
Can I drive with P0150?
Yes, for the short term — fuel control on Bank 2 falls back to safe defaults and the car remains drivable. Expect a fuel-economy penalty, and plan the fix soon to protect the catalytic converter on that bank.
Why does the Bank 2 sensor cost more to replace on some cars?
Pure access. On many transverse-mounted V6 engines, Bank 2 sits against the firewall, and its upstream sensor may require removing other components to reach — same part price, more labor hours.
Could this be wiring instead of the sensor?
Definitely — a general 'circuit malfunction' code is set for any unusable signal, and chafed wiring or a corroded connector produces one just as readily as a dead sensor. An inspection of the harness is cheap insurance before buying parts.
Seeing P0150 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0150 for my vehicleRelated trouble codes
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.