28/09/2025
HIGH FUEL CONSUMPTION
Whether we’re fleet managers or private vehicle owners, we’ve all dreaded driving into the petrol station at some point. Or even on multiple occasions because we know that money will leave our pockets for every drop filling our tanks. High fuel consumption in petrol engines is caused by many factors, but I'm going discuss on one of the major factors which is LAMBDA SENSOR
WHAT IS LAMBDA SENSOR
Is a measuring probe that monitors the car’s air-to-fuel ratio and relays the information to the car’s ECU (engine control unit). The ECU can then regulate the air and fuel mixture so that your car runs as cleanly and efficiently as possible.
It also plays an important role in controlling Emission systems in our cars—making them not only better for the environment, but easier on your wallet by improving fuel efficiency.
TYPES OF LAMBDA SENSOR
(1) Binary lambda sensor
(2) Universal lamda sensor
The binary sensor generates a change in electric voltage depending on the oxygen level in the exhaust. It compares the residual oxygen content in the exhaust with the oxygen level of the ambient air and identifies the transition from a rich mixture (lack of air) to a lean mixture (excess air) and vice versa.
The universal lambda sensor is extremely accurate when measuring both a rich and lean air/fuel ratio. It has a greater measuring range and is also suitable for use in diesel and gas engines.
SYMPTOMS OF FAULTY LAMBDA SENSOR
Like any car part, lambda sensors have a limited life span. Things like soot buildup, oil, salt, dirt, or contaminated fuel can all lead to them failing early.
There’s a few common symptoms that can point to a faulty oxygen sensor, so let’s take a look at them:
(a) High fuel consumption
(b) Rotten egg smell (rich mixture)
(c) Poor fuel economy (rich mixture)
(d) Black smoke from exhaust (rich mixture)
(e) Engine misfires/rough idle (lean mixture)
(f) Engine stalling (lean mixture)
(g) Trouble starting your car (lean mixture)
(h) Check engine light comes on
If you leave it too long, a faulty oxygen sensor can lead to problems with fuel economy and efficiency, as well as causing engine damage.
WHAT TO DO WHEN THIS SENSOR IS BAD
1. Get a Diagnostic Scan
Use an OBD-II scanner: Connect a scanner to your vehicle's diagnostic port to read the error codes.
Confirm the fault: The codes will indicate a test failure, not necessarily a specific faulty part. Use the scanner to check live data and compare the readings from the suspect sensor to a known working one to confirm the sensor itself is faulty.
2. Replace the Sensor
Do not drive the car: A bad lambda sensor causes improper fuel-air mixtures, which can lead to poor fuel economy and potentially damage the catalytic converter.
3. Clear the error codes: After replacing the sensor, use the scanner to clear the codes and ensure the check engine light is off.
When to Seek Professional Help
If you're unsure: If you're not comfortable performing the diagnostic or replacement yourself, VISIT BOSEV AUTO NIG LTD to avoid further damage