Your car engine’s air-fuel ratio has a considerable bearing on
fuel consumption and air pollution. For this reason, modern cars use an exhaust
gas oxygen (EGO) sensor mounted in the exhaust system to continuously
monitor air-fuel ratios and generate corresponding output voltages. This
information is then fed to the engine management computer (EMC) which
continuously adjusts the mixture to provide optimum power and economy,
consistent with low exhaust emissions.
As can be imagined, if the EGO sensor is not functioning
correctly, engine performance suffers and this can lead to very high fuel bills.
Conversely, a properly functioning sensor ensures good engine performance
and helps keep fuel costs down – something that’s even more important than ever
given the recent petrol price hikes.
A system that’s in good nick also minimises air pollution. In
modern cars, the combustion products from the engine are made safe by a
catalytic converter which is mounted in the exhaust system. Combustion
byproducts such as carbon monoxide (CO) are converted to carbon dioxide
(CO2), unburnt hydrocarbons to CO2 and water
(H2O) and nitrous oxide (NO) to nitrogen (N2) under the
action of the catalysts within the converter.
- Suits vehicles with Zirconia EGO probes
- Compact size
- 3-digit LED readout plus 7-LED bargraph display
- Dot or bar mode option for bargraph
- Air-fuel ratio matched for Bosch LSM11 (0258104002) EGO probe
- Indicates air-fuel ratios from 11.8 to 20.6 for petrol
- Indicates air-fuel ratios from 12.7 to 21.5 for propane/LPG
- Fully lean and fully rich air-fuel indication
- Bargraph display follows the non-linear response of the EGO sensor
- 13 indication levels in dot mode;, 7 levels in bar mode
- Fast 220ms update time for bargraph; 440ms for 3-digit display
- Automatic display dimming
- 0-1V display for setting up adjustments
Note: this device is not suitable for use on cars that run on leaded petrol. If your car doesn’t already have an EGO sensor, you can fit one yourself but the engine must run on unleaded fuel, propane or LPG in order to use the Fuel Mixture Display continuously (leaded petrol poisons the sensor).
However, this only works properly if the air-fuel ratio is held
within certain limits. And that in turn is dependent on the EGO sensor. An EGO
sensor, by the way, does not last indefinitely. Depending on the car, it’s
usually a good idea to replace it every 50,000 to 80,000km.