The Pair of NOx (Nitrogen Oxide) Sensors – OEM 55487663 & 55495340 is a complete emissions control sensor set specifically designed for Vauxhall/Opel Insignia B and Zafira Tourer C vehicles equipped with the 2.0 CDTi diesel engine. These NOx sensors measure nitrogen oxide levels in the exhaust gases at two key positions — before and after the Selective Catalytic Reduction (SCR) system — and relay this data to the vehicle’s engine control unit (ECU). Using both sensors helps the ECU optimise AdBlue dosing, improve combustion efficiency, and ensure compliance with emissions regulations while maintaining engine performance and reducing harmful pollutants.

OEM Number: 

TVAU55598161 - Front, Position 1, Pre Cat, Before SCR Catalytic Converter

5WK97227, 0899203, 55512348, 55 512 348, 8 55 599, 855599
55598161, ANS1019-12B1, 70680409, 69007, 710870M, 0899203
NOX1K002, 2203220039 01, 220322003901, LW8161S
241902710, DN14040414, 9 3517 1, 935171, 70680409
69007, LNX010, LSN008, 0899203, 0940002, V40-72-0054

TVAU55598169 - REar, Position 2, After SCR Catalytic Converter

70880, NOX1K001, 9 3518 1, OP980450, 70680410, 69006, LNX009
0899204, 55598169, 8 55 601, 855601, 5WK97228, 220322003901
70680410, 0899204, 70880, 55598169, 855601, ANS1015-12B1
2203220039 01, 5WK9 7228, 2211180025 01, 221118002501
LW8169S , 9 3518 1, 935181, OP980450, LSN007

Product Details

Placement on Vehicle: Before SCR Catalytic Converter & After SCR Catalytic Converter

Fitting Position: Front, Rear, Position 1, Position 2, Pre Cat, Post Cat, BOTH SIDES

Thread Size: M20 x 1.5

Number of Pins: 6 Pin Connector

Spanner Size: 22

Connector Shape: Rectangular

Cable Length: 590 mm

Operating Mode: Electric

Voltage: 12 V

Quantity: Pair

Make	Model	Variant	Type	Engine	Chassis	Year
Opel	Insignia A Country Tourer	Diesel Estate	2.0 CDTI 4x4	1956cc 125KW 170HP B 20 DTH	AWD A G09	2014-2017
Opel	Zafira Tourer	Diesel MPV	2.0 CDTi	1956cc 125KW 170HP B 20 DTH;D 20 DTH	FWD C P12	2015-2020
Opel	Zafira Tourer	Diesel MPV	2.0 CDTi	1956cc 96KW 130HP A 20 DT;B 20 DTJ;D 20 DTJ;Y 20 DTJ;Z 20 DTJ	FWD C P12	2011-2020
Vauxhall	Insignia	Diesel Estate	2.0 CDTI	1956cc 125KW 170HP B 20 DTH	FWD Mk I (A) G09	2014-2017
Vauxhall	Insignia	Diesel Estate	2.0 CDTI 4x4	1956cc 125KW 170HP B 20 DTH	AWD Mk I (A) G09	2014-2017
Vauxhall	Zafira	Diesel MPV	2.0 CDTi	1956cc 125KW 170HP B 20 DTH	FWD Mk III P12	2015-2018
Make	Model	Variant	Type	Engine	Chassis	Year

Our SKU : TVAU55598169-8161PAIR_94

All our NOX SENSOR NITROGEN OXIDE SENSORS (PAIR) FOR are OEM quality and reliable after-market car parts. This Nox Sensor Nitrogen Oxide Sensors (Pair) is specifically compatible with Opel: Insignia A Country Tourer, Zafira Tourer, Vauxhall: Insignia, Zafira.

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.

Key Benefits

• OEM-Referenced Pair: Supplied as a matched sensor set covering both NOx positions (pre-SCR and post-SCR), built to fit vehicles originally equipped with OE part numbers 55487663 & 55495340 — ensuring correct function and wiring compatibility.

• Enhanced Emissions Control: By providing accurate readings of nitrogen oxide in exhaust gases, these sensors help the ECU fine-tune SCR and combustion strategies, reducing harmful NOx emissions and supporting cleaner exhaust output.

• Restores Engine & ECU Performance: Faulty or degraded NOx sensors can trigger warning lights, reduced power modes, inefficiencies in fuel use and trouble codes related to SCR performance — replacing them with a pair addresses these issues.

• Durable Diesel-Grade Construction: Designed to withstand high heat, corrosive exhaust environments and long-term use, ensuring reliable performance over extended distances and driving conditions.

• Wide Compatibility on Diesel Models: Ideal for Vauxhall/Opel Insignia B (Z18) and Zafira Tourer C models with the 2.0 CDTi diesel engine (e.g., B20DTH / D20DTH variants) — check your exact engine and old sensor numbers to confirm fitment.

Frequently Asked Questions (FAQs)

Q1: What does a NOx sensor do?
A NOx (Nitrogen Oxide) sensor measures levels of nitrogen oxides in the exhaust and sends that data to the ECU, which uses it to regulate the SCR (Selective Catalytic Reduction) system and improve emissions control.

Q2: Why does this product include two sensors?
Diesel vehicles equipped with SCR typically use two NOx sensors — one before and one after the SCR catalyst. This dual setup lets the ECU monitor how effectively the SCR system reduces NOx emissions.

Q3: Which vehicles are these sensors compatible with?
This NOx sensor pair fits Vauxhall/Opel Insignia B (Z18) and Zafira Tourer C 2.0 CDTi diesel models. They are most common on cars from about 2017 onwards with 2.0 litre CDTi engines — verifying your old part number and engine code is recommended.

Q4: What are signs the NOx sensors are failing?
Typical symptoms include the check engine or emissions warning light, reduced performance, poor fuel economy, failed emissions tests or SCR-related fault codes — often due to incorrect NOx readings or sensor degradation.

Q5: Is replacing both sensors necessary?
Yes — replacing both sensors together ensures the emissions system works correctly and avoids imbalance in readings that can compromise SCR function or trigger ECU errors.