Figures from the Driver & Vehicle Standards Agency (DVSA) show that following the issue of MoT extensions during the first lockdown nearly two million cars may be being driven on UK roads without a certificate.

Extensions were granted for 9.58 million vehicles and the DVSA says 1.86m vehicles still haven’t had a new MOT.

It is urging motorists to carry out basic safety checks on their vehicles and is reminding them that an MOT garage is a good place to get their vehicle checked if they are unsure about anything.

NGK – the leading supplier of original equipment (OE) spark plugs, glow plugs and NTK engine management sensors – says garages should be prepared for when these vehicles are eventually tested.

Mark Hallam, Marketing Manager, NGK Spark Plugs (UK) Ltd, said: “As more and more vehicles return to the UK’s roads following the easing of the COVID restrictions, it is vitally important that motorists ensure they are roadworthy and in the best possible condition by getting them checked at their local independent garage.

“When the vehicles that are due an MoT are eventually tested, many thousands will fail on emissions which will lead to increased demand for the replacement of Lambda sensors.”

NGK is the world’s largest manufacturer of Lambda sensors and supplies a market-leading range to the UK aftermarket under the NTK brand name.

There are good reasons why NTK Lambda sensors are the No.1 choice of vehicle manufacturers (VMs) around the world, they are ‘Similar but different’.

NGK says the experience it has in supplying the VMs worldwide allows it to offer exactly the right sensor for every vehicle application.

The company advises distributors to encourage garages to always go with a bespoke OE-quality Lambda sensor and steer well clear of ‘universal sensors’. 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.

NGK says distributors should help educate garages by ensuring they fit a new NTK Lambda sensor whenever they replace a vehicle’s catalytic convertor.

A worn or failed sensor can result in drastically reduced control of the fuelling system which could result in increased fuel consumption, uneven running, generally poor performance or failure of an MoT emission test, so replacement is good news for the customer, garage and distributor.

NGK recommends 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.  Garages need to look for slow response times, output range and heater function.

Contaminants from poor quality oils and fuel which remain in the exhaust gases can become deposited on the sensor element affecting its operation. Even coolant from a leaking head gasket can reach the element.

For more information, please visit the website www.ngkntk.com