Invented by Robert Bosch GmbH in the early 1960s, the Lambda sensor, aka oxygen sensor or air/fuel ratio sensor is one of those auto components that packs small but plays big. The role Lambda sensors play in governing engine performance cannot be overstated – in essence, the Lambda sensor tells the electronic control unit (ECU) how to regulate the air/fuel mixture going into the cylinders. If a Lambda sensor is faulty, the engine will not receive the optimum air/fuel blend and as a result, will run poorly with increased fuel consumption and excessive exhaust emissions.
OEMs recommend replacing Lambda sensors around the 100 000km mark, but they do last longer if the car is well maintained. Nonetheless, most vehicles today are equipped with Lambda sensors and your workshop should be equipped to diagnose old Lambda sensors and to source and fit quality replacement units.
Here’s what you’ll need...
• The vehicle’s service manual to locate the Lambda sensors. Newer vehicles will have at least two Lambda sensors – one upstream of the catalytic
converter and one downstream of the cat unit.
• An OBD2 engine scan tool to ascertain if a Lambda sensor is faulty before you remove and replace it. Get one at www.takealot.com
• A multimeter to check the resistance [Ohm) of the unit. Visit www.startmycar.co.za
• A Lambda sensor socket to remove and replace sensors with ease. Visit www.takealot.com
• A new DOE Lambda sensor from www.startmycar.co.za
• A tube of Anti-seize paste to apply to the threads of the new sensors to enable easy removal during future servicing. Visit www.startmycar.co.za
And now the diagnostic and replacement tasks...
• Make sure the engine is cool.
• Locate the Lambda sensor. If a service manual is unavailable, check online or contact a dealer workshop.
• Plug in the OBD2 scanner and determine whether or not the Lambda sensor is faulty. If a ‘Check Engine’ warning light is illuminated on the car’s dash,
it’s probably due to a faulty Lambda sensor.
• Remove the plastic Lambda sensor connector at the ECU.
• Check Ohm and voltage reading with a multimeter connected to the black wires on the Lambda sensor connector. If there is a low or zero Ohm
reading, the unit is faulty and should be replaced.
• Remove the old sensor and fit the new DOE Lambda sensor using the special Oxygen Sensor Socket tool and a spot of anti-seize paste.
• Start the car and take it for a short test drive. If the ‘Check Engine’ warning light doesn’t come on, you’ve solved the problem.
Bottom line – Aftermarket Lambda sensors aren’t expensive and the DOE range of Lambda sensors from www.startmycar.co.za is genuine OE-quality, guaranteed. By becoming a Lambda sensor specialist, you’ll help your customers save fuel and the environment while restoring their car’s engine to peak performance!