Suitable for Mazda MX-5 Mk3 / NC 1.8 and 2.0 petrol models up to approximately September 2008 production. This is the pre-catalyst / upstream / first lambda sensor in the exhaust system.
DENSO DOX-0518 is a Direct Fit heated broadband oxygen / lambda sensor for the Mazda MX-5 Mk3 / NC. It is supplied with the correct electrical connector and is designed as a direct replacement for the original upstream sensor, without requiring a universal sensor to be spliced into the vehicle wiring.
This sensor is positioned before the catalytic converter and acts as the regulating sensor used by the engine-management system to monitor the oxygen content of the exhaust gases. The ECU uses this information when controlling the air-fuel mixture.
Product Specifications
- Brand: DENSO
- Product range: Direct Fit
- Product type: Oxygen / lambda sensor
- Sensor type: Broadband oxygen sensor
- Sensor design: Heated, finger-type sensor
- Installation position: Upstream / pre-catalyst
- Function: Regulating sensor
- DENSO part number: DOX-0518
- DENSO reference: 211200-4280
- DENSO interchange reference: 234-9088
- Thread size: M18 x 1.5
- Cable length: 225 mm
- Connector: Direct-fit vehicle connector
- Number of pins: 4
- Thread: Pre-greased
- Weight: Approx. 115 g
- GTIN / EAN: 8717613048436
- Mazda OE reference: LFG1-18-8G1A
- Quantity required per vehicle at this position: 1
- Quantity supplied: 1 sensor
Important Fitment Note
DOX-0518 is the upstream / pre-catalyst sensor and must not be confused with the downstream / post-catalyst sensor. The two sensor positions perform different functions and should not be assumed to be interchangeable.
Application data specifically identifies DOX-0518 as the pre-catalyst regulating sensor for MX-5 NC vehicles produced up to approximately September 2008. Later Mk3.5 / Mk3.75 vehicles may use a different sensor specification.
Typical Reasons for Replacement
An oxygen sensor may require replacement because of internal sensor deterioration, heater-circuit failure, contamination, damaged wiring or connector problems. A faulty sensor can contribute to an engine-management warning light, incorrect mixture control, poor running or increased fuel consumption, although these symptoms can have other causes and should be properly diagnosed before replacing components.
Fitment Advice
Confirm that the sensor being replaced is the upstream / pre-catalyst sensor before removal. Where possible, compare the connector, cable arrangement and OE reference with the existing sensor.
For imported, modified or previously repaired cars, matching the part number or component style on the part being replaced is recommended.
Other Items to Consider
- Downstream / post-catalyst oxygen sensor if diagnosis identifies a separate fault
- Exhaust manifold and exhaust gaskets
- Exhaust-system fasteners
- Ignition and service components where poor running is being investigated
Useful Tools / Consumables
- Suitable oxygen-sensor / lambda-sensor socket
- Ratchet and extension as required
- Torque wrench
- Penetrating fluid for seized exhaust threads where appropriate
Difficulty Guide
DIY Difficulty: Moderate. The sensor is threaded into the exhaust system and can become difficult to remove after prolonged exposure to heat and corrosion. Correct identification of the sensor position and careful handling of the electrical connector are important.
Why DENSO?
DENSO is a long-established Japanese automotive component manufacturer and major developer of engine-management technology. Its Direct Fit oxygen and air-fuel ratio sensors are application-specific replacements supplied with the appropriate connector and wiring arrangement, drawing on DENSO's extensive experience in emissions and engine-control systems.
What's in the Box?
- 1 x DENSO DOX-0518 Direct Fit oxygen / lambda sensor
Installation Notes
Allow the exhaust system to cool before starting work. Disconnect the electrical connector before removing the existing sensor and avoid twisting or damaging the wiring during installation.
The replacement sensor is supplied with a pre-treated thread. Take care not to contaminate the sensing element and tighten the sensor using the appropriate installation procedure.
| Make | Model | Sub Variant | Chassis / Code | Years | Power (PS) | Engine Codes | Fuel | Transmission | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Mazda | MX-5 Mk3 / NC | 1.8 | NC18 | 03/2005-09/2008 | 126 | L828 / L831 / L8-VE | Petrol | Manual / Automatic where fitted | Upstream / pre-cat regulating sensor; production up to 09/2008; 1 required at this position |
| Mazda | MX-5 Mk3 / NC | 2.0 | NC18 | 07/2005-09/2008 | 160 | LFG7 / LFG8 / LF-VE / LFY7 / LFZD | Petrol | Manual / Automatic where fitted | Upstream / pre-cat regulating sensor; production up to 09/2008; 1 required at this position |
| Vehicle Manufacturer | OEM Reference Number |
|---|---|
| Mazda | LFG1-18-8G1A |