Lambda sensor

[daz_g]

I have a 2 litre zetec engine '97 using a ford ecu. I'm using a westfield manifold with a threaded boss already on for the sensor. There are 4 wires on my loom for the lambda (oxygen sensor).

Does anyone have a similar set up and know of any make or part numbers for the sensor that i would need to get?

[cidersurfer]

Extracts shamelessly stolen from the Megasquirt manual here...

One, three and four wire narrow band O2 sensors [NB], and two wide band sensors [WB] are currently available on the market.

Narrow band O2 sensors are designed to measure stoichiometric [chemically correct] air/fuel mixtures [A/F] of 14.7:1 to allow catalytic converters to work efficiently. Narrow band sensors always have one wire for the sensing function. Additional wires are for the heater and its ground (3 wire sensor), and possibly an additional wire to ground the sensor itself (4 wire). The sensor needs to be quite hot to operate. The heater keeps the sensor at operating temperature under more conditions.

The difference between the heated (3 or 4 wire) O2 sensor and a non-heated (one wire) sensor is the A/F ratio sensing of warm up and low load conditions. The heated sensor uses an internal coil to heat the ceramic element to the desired 400° Celsius in 30 or 40 seconds. This temperature is also maintained when the car is at idle for extended periods of time or is under low load conditions where the exhaust gas temperatures fall below 400° C.

Under other operating conditions the exhaust gas temperature will be much greater than 400° C. and heating is not necessary. The non-heated sensor relies on the exhaust gas heat to keep it at its operating temperature. This works most of the time but there is still times that it might drop below its desired operating temperature and show a leaner than actual mixture as its output drops to zero.

A 1-wire sensor is as good as a 3-wire provided that it is always at operating temperature. If you cruise around for a bit with the engine at low load, the O2 sensor COULD cool down. If you do not have exhaust gas temperature [EGT] monitoring then you cannot be sure. Once warm, a 3-wire O2 sensor will stay warm. For most of us the one wire will prove to be adequate. A 4-wire has a shielded cable. You only need to ground the shield at one end. In many installations there is not enough voltage drop from the manifold to ground to make shielding worth the bother, but every little helps. So the more wires the O2 sensor has, the more situations in which the sensor will be active and accurate, but you are still stuck with knowing whether you are rich or lean, but not by how much.

If your car did not come with an oxygen sensor, you can add one. The thread for all oxygen sensors [including wide-band] is:18mm x1.5mm - i.e., a metric thread 18mm in diameter with a pitch of 1.5mm, the same as 18mm spark plugs. The hex portion is 22mm, and a 7/8" wrench will work for installing/removing.

Pick one from this list, they are all very similar. Mines off a scrap Fiat Punto!

HTH Chris  

[Flappa]

WF use Fuelparts

www.fpuk.co.uk

I may be able to sort out a part number if that helps. Look on their web site and go to contacts and search for a local stockist.

Type: LB1031

Lambda 4 wire Zirconia

Location: EM-LB-C-4