NTK
Direct Fit Oxygen Sensor

NTK 25174 Oxygen Sensor - Downstream or Downstream Right

Brand NTK 25174
Position Downstream Right and Downstream
Wiring Harness Length 38.2500
Sensor Type Heated
Universal Or Specific Fit Specific
Wire Quantity 4
Thread Diameter 18.000
Mounting Type Threaded
Product line Direct Fit Oxygen Sensor
Fits Audi · 6 vehicles

Direct fit design. Built for specific applications with OE-style fit, form, and function.

Heated sensor. Supports responsive exhaust feedback with a 4-wire configuration.

OE-tested quality. Extensively tested during manufacturing to meet or exceed OE specifications.

Cross-references BBB Industries 13944, 06E906265E and 75-3403 for the same application. See all 4.

$193.31Free shipping
In stock · usually ships same day before 1pm CST
Step 1 — Confirm fitment
Free return shipping if it doesn't fit when you check fitment here first.

Select your vehicle to confirm fitment
Verify this part fits before purchasing — free returns if it doesn't
Step 2 — Quantity
Order total $193.31
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.

Direct Fit Oxygen Sensor for Audi

The NTK 25174 is a direct fit oxygen sensor built for specific Audi applications that require a heated, threaded sensor with a 4-wire design. It is engineered for accurate exhaust monitoring and OE-style fit, form, and function.

  • Specific-fit oxygen sensor for targeted applications
  • Heated sensor design for responsive exhaust feedback
  • 4-wire configuration for proper signal and heater circuit operation
  • Threaded mounting type for direct replacement installation
  • 38.2500 wiring harness length for application-specific routing

Fitment and Application Details

Fits 2010-2011 Audi A6, downstream. Fits 2009 Audi A6 Quattro, downstream right. Fits 2006 Audi A4, downstream right. Fits 2006 Audi A4 Quattro, downstream right. Fits 2005 Audi A4 Quattro, downstream right. This part cross-references BBB Industries 13944 and Interchanges 06E906265E for the same application.

NTK positions this oxygen sensor line as a direct fit solution backed by extensive manufacturing tests and OE application coverage. The 25174 is part of NTK's broader sensor program, which focuses on streamlined coverage for import and domestic vehicles while maintaining OE-level fit and function. For Audi A4 and Audi A6 applications, the 25174 supports accurate replacement when the original sensor has aged, failed, or triggered drivability concerns.

Common Replacement Reasons

  • Check engine light related to oxygen sensor performance
  • Incorrect air-fuel ratio readings
  • Reduced fuel economy from a failing sensor
  • Slow sensor response or heater circuit faults
  • Emissions test failures tied to exhaust monitoring issues

Installation Notes

Verify the connector, harness length, thread diameter, and downstream position before installation. Confirm chassis breakpoints and engine-specific notes listed in the fitment data for Audi A4, Audi A4 Quattro, Audi A6, and Audi A6 Quattro applications. Use the vehicle's service information to match the sensor location and routing requirements.

Quality Assurance

NTK states that its oxygen sensors are extensively tested during manufacturing to meet or exceed OE specifications. The brand is part of the NGK family of products and is recognized as a major original equipment oxygen sensor supplier.

This part fits 6 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelLitersCylindersPositionNotes
2011AudiA63.2LV6DownstreamCyls. 1-3; B1S2; OE MFR: NTK; Direct Fit Oxygen Sensor
2010AudiA63.2LV6DownstreamCyls. 1-3; B1S2; OE MFR: NTK; Direct Fit Oxygen Sensor
2009AudiA6 Quattro3.0LV6Downstream RightB1S2 oxygen sensor meets OEM standards.; Direct Fit Oxygen Sensor
2006AudiA43.2LV6Downstream RightTo Chassis # 8E-6-035 000; OE MFR: NTK; Direct Fit Oxygen Sensor
2006AudiA4 Quattro3.2LV6Downstream RightTo Chassis # 8E-6-035 000; OE MFR: NTK; Direct Fit Oxygen Sensor
2005AudiA4 Quattro3.2LV6Downstream RightB1S2 oxygen sensor meets OEM standards.; Direct Fit Oxygen Sensor
Directly replaces or cross-references 4 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
BBB Industries — 1394406E906265E75-3403234-4408