Prevent premature failure

Tim Howes, Deputy General Manager of NGK, on the benefits of bespoke over universal lambda sensors

Published:  20 March, 2014

By Tim Howes

We recommend that the function of the sensor is checked every 20,000 miles or annually. The emissions check as part of the current MOT test samples the exhaust gases to monitor the efficiency of the engine, exhaust system and engine control systems. The Lambda sensor is a vital part of this system and its function is therefore influenced by many other components.

A malfunction of an associated part may directly affect the performance of a sensor. An oscilloscope and gas analyser is a much more accurate way of assessing sensor performance than relying on fault codes alone. Look for slow response times, output range and heater function.

A 'universal' Lambda sensor is designed to cover as many applications as possible by splicing in the connector from the unit being replaced. In theory, this sounds like a good idea. In practice the potential for a mismatch with the vehicle's system or subsequent premature failure is very high.

Apart from the more obvious choices of the number of wires and whether it's a zirconia or titania type, there are several base sensor designs to be considered with differing characteristics including heater element performance, response time performance and even internal electrical grounding.

Once the correct choice has been made you need to worry about making sound electrical connections and ensuring that you marry the lead wires correctly. Sensor manufacturers' wiring colours differ so you cannot always simply join the matching colours. For some sensors, soldering the leads together is out of the question as they may need to 'breathe' through the tiny gaps in the lead wires and poor quality crimping can lead to water or oil ingress which can damage the sensor or affect its performance.

Apart from all that, if you have not even disconnected the multiplug when splicing in the new unit you run the risk of missing such problems as corroded or damaged connector pins. In addition, many vehicles now use wide band sensors and for this type there is no substitute other than the correct original equipment (OE) specification item.

Find out more

Related Articles


Search

Sign Up

For the latest news and updates from Aftermarket Magazine.


Poll

Where should the next Automechanika show be held?



Facebook


©DFA Media 1999-2016

Mentés