| Manufacturer Part Number | 17351 |
| Type | Oxygen Sensor / O2 Sensor / Air-Fuel Ratio Sensor |
| Placement on Vehicle | Upstream / Front |
| Number of Wires | 5 |
| Oxygen Sensor Type | Wideband |
| Sensor Type | Heated |
| Wire Leads Length | 58.86 inches (1495 mm) |
| Thread Diameter | 18 mm |
| Hex Size | 22 mm (0.88 inch) |
| Housing Material | Stainless Steel |
| Features | Direct Fit, OE Connectors, Pre-coated Threads |
| Fitment Type | Vehicle Specific |
Vehicle Compatibility
| brand | Model | year range | Engine/Remarks |
|---|---|---|---|
| Audi | A4 | 2001–2006 | 1.8T/2.0/3.0 |
| Audi | A4 Quattro | 2001–2005 | 1.8T/3.0 |
| Audi | A8 Quattro | 2004–2006 | - |
| Audi | TT | 2001–2006 | 1.8T/3.2 |
| Audi | TT Quattro | 2001–2002 | - |
| Bentley | Continental | 2003 | 6.0L W12 |
| Volkswagen | Beetle | 2001–2005 | 2.0L |
| Volkswagen | EuroVan | 2001–2003 | 2.8L VR6 |
| Volkswagen | Golf | 1999–2006 | 2.0L |
| Volkswagen | Jetta | 1999–2005 | 2.0L/1.8T |
| Volkswagen | Passat | 2000–2005 | 1.8T/2.8L |
| Volkswagen | Phaeton | 2004–2006 | 4.2L V8 |
| Volkswagen | Touareg | 2004–2007 | V6/V8 |
Product Description
The Bosch 17351 is a premium wideband upstream oxygen (O2) sensor designed for a broad range of Audi, Volkswagen, and select Bentley models from 1999 to 2007. Bosch invented the automotive oxygen sensor in the late 1960s and remains the world's leading OE supplier to car manufacturers.
How It Works: This 5-wire heated wideband sensor continuously monitors the oxygen content in the exhaust stream. Unlike traditional narrowband sensors, the wideband sensing element produces a proportional output signal that allows the ECU to precisely measure air-fuel ratios from as rich as 9.0:1 to as lean as free air. The ECU uses this data to maintain the optimal 14.7:1 stoichiometric ratio, maximizing fuel efficiency and minimizing emissions.
When to Replace: Common failure symptoms of a failing upstream O2 sensor include:
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Illuminated check engine light with DTC codes such as P0130, P0133, or P0135
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Reduced fuel economy (3-5 MPG loss is common)
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Rough engine idle or hesitation during acceleration
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Failed emissions inspection
Key Features:
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Wideband design – Provides precise air/fuel measurement for modern engine management systems
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True direct-fit – OE-style connector and harness with threads pre-coated with anti-seize compound for plug-and-play installation
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Double laser-welded stainless steel body – Fully submersible and sealed to protect against exhaust contaminants
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100% functional quality tested – Each sensor undergoes full functional testing before leaving the factory
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Fast-acting heater – Reaches operating temperature within seconds for rapid closed-loop operation
Installation Note: Professional installation is recommended. Allow the exhaust system to cool completely before removal. Use a 22mm oxygen sensor socket and apply anti-seize to threads if not pre-coated. Bosch recommends replacing oxygen sensors every 100,000 miles for optimal engine performance.
Compatibility Check: Please verify your vehicle's year, make, model, and engine size before ordering. This sensor is an upstream/front position O2 sensor - verify whether your vehicle requires upstream replacement. Not compatible with diesel engines.