At DDP AutoParts, we supply a high-quality NOx (nitrogen-oxide) sensor for the Audi A4 B9 2.0 TDI (from 2015 onwards), specifically for the OEM part 8W0907807R. This sensor sits before your DPF / SCR system and precisely monitors NOx levels in the exhaust, allowing the control unit to regulate AdBlue injection and emissions in real time. A faulty NOx sensor can lead to emission faults, increased AdBlue consumption or warning lights — but with our aftermarket replacement, you get reliable performance, long-term durability, and full emissions compliance — at a better price than OEM.

OEM Number: 0281007857, 0281007858, 0281008749, 8W0907807R, 8W0907807BJ, 8W0907807JJ, 

Fitting Position : before soot particulate filter

Placement on the vehicle : Front, Before DPF

Number of pins : 5-pin connector

Connector Shape : oval

Voltage : 12 V

Cable Length : 1,000 mm

Thread Size : M20*1.5

Quantity : 1

Our SKU: TA8W0907807BJ_94
 
All our Nox Sensor For Audi A4 B9 2.0 Tdi 2015-onwards Front Before Dpf 8W0907807R are OEM quality and reliable after market car parts. This Nox Sensor For Audi A4 B9 2.0 Tdi 2015-onwards Front Before Dpf 8W0907807R is specifically compatible with Audi: A4, A4 Allroad, .

Please use our make-model-year tool to check this part's compatibility with your vehicle. However, please note that our tool is for reference only and we recommend that you check the part number on your old unit prior to purchasing.

If you are still not sure about the compatibility of this part to your vehicle, please supply us with the VIN number or Reg number in our live chat or contact form! You can also find details on our purchasing & shipping guide here.

❓ Frequently Asked Questions

1. What exactly does this NOx sensor do in my A4 B9 2.0 TDI?
   The sensor measures the concentration of nitrogen oxides in the exhaust gas before the DPF / SCR system. It sends this data to your car’s ECU or urea injection unit, helping to manage AdBlue dosing and ensure clean, compliant emissions.

2. Which models and engines is this part compatible with?
   This sensor is designed for the Audi A4 B9, 2.0 TDI (from ~2015), using the OEM reference 8W0907807R. According to parts sources, it’s used in the “before DPF” position.

3. Is this a genuine Audi / OEM part or an aftermarket alternative?
   This is a high-quality aftermarket equivalent, based on the Bosch sensor 0281008749 which matches OEM reference 8W0907807R. You get OEM‑level performance with a more affordable price.

4. What are the symptoms that my NOx sensor might be failing?

   • Emission-related warning lights or NOx / SCR fault on the dashboard.

   • Diagnostic trouble codes related to NOx sensor circuit or AdBlue system.

   • Poor AdBlue / urea efficiency (more AdBlue consumption than normal).

   • Reduced performance / derating if the ECU cannot correctly interpret NOx levels.

5. How hard is it to fit / replace this sensor?

   • The sensor is usually located on or around the exhaust system, so you’ll likely need under‑car access.

   • Make sure electrical connections are properly secured and protected.

   • After installation, you should clear any fault codes using a diagnostic tool — this allows the ECU or urea system to re‑read the new sensor correctly.

6. What can cause a NOx sensor to fail?

   • Contamination from soot, particulates, or poorly combusted fuel.

   • Vibration or heat stress damaging the sensor internals.

   • Corrosion or poor connector seal, leading to faulty readings.

7. Will replacing the NOx sensor fix all emission system faults?
   It can resolve many NOx / AdBlue-related warning lights or errors, especially if the sensor was the root cause. However, if there are more serious issues (e.g. SCR catalyst damage), further diagnostics may be needed.

8. Do I get a warranty or after-sales support from DDP AutoParts?
   Yes — this part comes with our standard parts warranty. If the sensor doesn’t work as expected or a fault persists after fitting, our support team will help you troubleshoot, return, or replace it.

9. Why buy this NOx sensor from DDP AutoParts instead of getting it from Audi or a main dealer?

   • Cost efficiency: Much cheaper than the OEM part.

   • Quality: We source from trusted aftermarket manufacturers using the Bosch reference.

   • Support: We guide on fitment, fault-code clearing, and any post-install checks.

   • Availability: We keep emissions-critical parts like this in stock to minimise wait times.