Why the Check Engine Light could reduce emissions and clean up our fleet.

The last 16 months have been a rollercoaster for electric vehicle sales. The rushed cessation of the Clean Car Rebate, and the introduction of RUC has seriously stalled our progression towards a cleaner fleet. The proportion of new electric passenger vehicle sales (BEV and PHEV) are now just 10.6% year to date (March data) whereas in 2023 they were 23% at this point.

Now that the adoption of zero emissions vehicles has become politicised, we need a secondary path to cleaning up our fleet. Note to politicians; your centrist voters want you to develop policies that have cross-party support for the good of the economy and the environment.

Our vehicle fleet is old. The average passenger vehicle is 15 years old in New Zealand. Older cars, even when well maintained are significantly higher emitters than their modern equivalents. We also have high levels of vehicle ownership, and so effecting a meaningful change in the composition of our fleet to reduce our emissions will take a concerted effort, and time.

We bring in cars from Japan that are typically eight years old, which theoretically is a third or even halfway through their life. Emissions standards and consumer preferences have changed significantly since when these vehicles we are importing today were built in 2017 or 2018.

Photo by Diego PH on Unsplash

Among the myriad of quirks of how our vehicle fleet is managed and manipulated by governments, one jumps out as a grave omission in our quest for lower emissions. We have no emissions based, in service testing. There is no requirement for the WOF testing station to check that the emissions exiting from your exhaust pipe are at an acceptable or safe level. However help is at hand, and it’s a small orange engine symbol on your dashboard; the Check Engine light.

Check Engine Lights can trace their origins back to the 80’s when OBD (On Board Diagnostics) were first introduced as part of smog controls in the US and Europe, to increase engine efficiency and reduce emissions. Since then, the complexity of engines and engine management has increased. Over time OBD2 has become the standard for vehicle diagnostics, to a point where a simple generic diagnostic tool is less than $100 and it can be plugged into almost any vehicle to read fault codes.

OBD2 was adopted as a standard in the US in 1996 and Europe in 2001, but critically in Japan in the late 90’s. Even though OBD2 now covers engine, transmission, ABS airbags among other things a serous fault in any of these triggers the Check Engine light, and so we have a basic way of identifying whether vehicles could have an emissions problem without having to add a probe to measure tailpipe emissions.

By simply having a ‘no vehicle should pass a WOF with a Check Engine light showing’ clause, we could identify the most polluting vehicles. A OBD2 port reading would identify whether the code was emissions related, and these vehicles could be rejected for further investigation.

New Zealand is relatively unique in our lack of emissions testing. This simple solution could help us use the vehicle’s own in-built emissions testing software.

It would be simple to add in a similar pass or fail for a DPF (Diesel Particulate Filter) warning light on the same basis.

While this is not a comprehensive fix for lowering our emissions for older light vehicle on our roads, it would play a part in identifying the worst polluters. Even targeting the worst 50% of polluting vehicles would pay dividends for motorist and the environment.

Its a simple idea, and one that should have merit.