A catalyst-efficiency or lean-mixture code does not prove an oxygen or air-fuel sensor has failed. Exact location and fit depend on the engine.
The source is a research lead, not a current SKU, price, supersession or exact VIN fitment check. Confirm the current manufacturer parts catalog and retailer listing before any purchase.
Read the Ford original: Gasoline OBD System Operation Summary MY 2024–2025 Source date: 2024-04-16; research checked: 2026-11-01.
Before ordering
Identify bank and sensor position from the vehicle service information, inspect companion codes and verify the current OEM number. Exhaust leaks and mixture issues can affect readings.
Safety
Exhaust parts become extremely hot. Sensor replacement and wiring diagnosis can require skilled work and exact procedures.
Bank and sensor position matter
A code involving Bank 1 Sensor 1 is not interchangeable with Bank 1 Sensor 2. The upstream and downstream sensors can have different connectors, functions and diagnostic paths. The vehicle's cylinder-bank layout must be confirmed from the exact engine information before identifying a physical location or ordering a part.
A P0420 report measures a catalyst system condition; a lean-code report reflects mixture correction. Either may coexist with oxygen-sensor readings without proving the sensor is bad. A heater-circuit code such as P0141 raises a different circuit question than catalyst efficiency. Check wiring, power and ground using the approved procedure before condemning a sensor.
Purchase gate
- Confirmed fault and exact bank/sensor position
- Current OEM number and supersession
- VIN, engine, emissions configuration and connector match
- Safe access and installation procedure for the hot exhaust area
Sources and scope
- Ford — Gasoline OBD System Operation Summary MY 2024–2025 Document: 2024-04-16 · Research checked: 2026-11-01
- Subaru — Bulletin 09-115-24: downstream oxygen sensor codes including P0141 Document: 2024-05-14 · Research checked: 2026-11-01
Research snapshot: 2026-11-01. Source documents may have newer revisions. Verify current instructions and VIN eligibility with the manufacturer.