Replacement Lambda Sensors

Why Aftermarket Sensors?

That’s an easy one. Cost. Standard sensors if bought from smart can be extortionate. It makes more sense to go for the cheaper option which can actually be exactly the same sensors that you would have bought from smart.

Important

This information relies on specs and information harvested from other sites. I can only pool this info into 1 place, I can’t guarantee the information is correct.

PLEASE CHECK THIS INFO TO YOUR OWN SATISFACTION BEFORE PURCHASING.

450 600cc

Manufacturer : NGK
Part No : OZA659-EE42
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 295mm

Manufacturer : Bosch
Part No : 0 258 006 563
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm

Manufacturer : Bosch
Part No : 0 258 986 615
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm
Thanks to Michael G for this info.

Manufacturer : Bosch
Part No : 0 258 005 733
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm
Thanks to Michael G for this info.

Manufacturer : Delphi
Part No : ES20312-12B1
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 280mm

Manufacturer : Bolk
Part No : BOL-C031818
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 200mm

Manufacturer : Bolk
Part No : BOL-C031821
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 200mm

450 700cc

Manufacturer : NGK
Part No : OZA659-EE42
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 295mm

Manufacturer : Bosch
Part No : 0 258 006 563
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm

Manufacturer : Bosch
Part No :0 258 986 615
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm
Thanks to Michael G for this info.

Manufacturer : Bosch
Part No :0 258 005 733
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm
Thanks to Michael G for this info.

Manufacturer : Delphi
Part No : ES20312-12B1
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 280mm

Manufacturer : Bolk
Part No : BOL-C031818
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 200mm

Manufacturer : Bolk
Part No : BOL-C031821
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 200mm

451 999cc Non Turbo (Not USA)

Euro 4

Manufacturer : NGK
Part No : OZA571-GB1
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 89
Length of Sensor & Cable : 300mm

Euro 5

Manufacturer : NGK
Part No : OZA603-MB16
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 89
Length of Sensor & Cable : 300mm

451 999cc Non Turbo (USA)

From what I can see:

The Upstream sensor is a wideband sensor with 5 wires.

Bosch 17444
Walker 350-35076
Denso 234-5071
NTK 24329

The downstream sensor is a narrowband sensor with 4 wires.

Bosch 16749
Walker 350-34360
Denso 234-4881
NTK 25186

451 999cc Turbo

Manufacturer : NGK
Part No : OZA571-GB1
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 89
Length of Sensor & Cable : 300mm

451 Diesel

45bhp (non DPF)

Manufacturer : Bosch
Part No : 0 258 017 134
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 350mm

Manufacturer : Metzger
Part No : 0893318
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 375mm

Manufacturer : Meat & Doria
Part No : 81577
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 410mm

54bhp (with DPF)

Manufacturer : Bosch
Part No : 0 258 017 014
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 350mm

Manufacturer : FAE
Part No : 75061
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 350mm

Manufacturer : Pierburg
Part No : 7.02604.44.0
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 450mm

Manufacturer : Vemo
Part No : V30-76-0036
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 350mm

Manufacturer : Metzger
Part No : 0893020
Position : Upstream
Number of Wires : 5
Length of Sensor & Cable : 410mm

452 Roadster

Manufacturer : NGK
Part No : OZA659-EE42
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 295mm

Manufacturer : Bosch
Part No : 0 258 006 563
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm

Manufacturer : Bosch
Part No : 0 258 986 615
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm
Thanks to Michael G for this info.

Manufacturer : Bosch
Part No : 0 258 005 733
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : 47
Length of Sensor & Cable : 300mm
Thanks to Michael G for this info.

Manufacturer : Delphi
Part No : ES20312-12B1
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 280mm

Manufacturer : Bolk
Part No : BOL-C031818
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 200mm

Manufacturer : Bolk
Part No : BOL-C031821
Position : Upstream & Downstream
Number of Wires : 4
Connector Type : None (crimp old connector)
Length of Sensor & Cable : 200mm

454 Forfour

Diesel

Manufacturer : Bosch
Part No : 0258017014
Number of Wires : 5
Connector Type : ?
Length of Sensor & Cable : 350mm

Petrol

Manufacturer : Bosch
Part No : 0258006566
Position : Upstream
Number of Wires : 4
Connector Type : ?
Length of Sensor & Cable : 478mm

Manufacturer : Bosch
Part No : 0258006568
Position : Downstream
Number of Wires : 4
Connector Type : ?
Length of Sensor & Cable : 348mm

Jargon Key

Upstream & Downstream

Upstream sensors are positioned between the engine and the catalytic convertor. Downstream sensors are placed into the catalytic convertor (big exhaust box thing).

Number of Wires

Most lambda sensors have 4 wires which generally indicates that they are standard zirconia sensors. If a sensor has 5 or 6 wires it is usually a wideband sensor.

Length of Sensor & Cable

Exactly that. The overall length, end to end of the sensor. I suppose it’s good to know that once the sensor is screwed into place that the wiring connector will reach the car’s connector.

Sensor Number

Apart from very early 600cc fortwos, all other fortwos have 2 lambda sensors. Bank 1, sensor 1 and bank 1, sensor 2.

Normally, sensor 1 is in the upstream position (nearest the engine) and sensor 2 is the downstream sensor (furthest from the engine).
The downstream sensor is usually in the catalytic convertor can. The upstream sensor is either in the turbo or the exhaust manifold.

Be careful with generic error code readers because they don’t always give out the correct data.
As I said earlier, the upstream sensor should be 1 and the downstream sensor should be 2.
However some OBD readers will label the upstream sensor as 0 and the downstream sensor as 1.

If you want to be 100% sure, disconnect both sensors and see if your code reader brings up error codes for 1 and 2 or 0 and 1.