Don’t bypass diesel’s emissions controls

Last November, the U.S. Environmental Protection Agency (EPA) released a report that claimed that, between 2009 and 2020, some 500,000 diesel-powered pickup trucks had their emissions systems completely disabled.

That number represents about 15 per cent of all sales of these trucks.

Like many other survey results from south of the border, and based on related news feeds up here, it’s safe to assume we have a similar problem here in Canada.

Diesel engines have evolved, and since around 2007 have been equipped with some effective yet very

complicated emissions systems, involving diesel exhaust fluid (DEF) injection, liquid-cooled exhaust gas recirculation (EGR) systems, and particulate matter filters (PMFS).

All of these systems are fairly expensive to maintain and repair, and when things go wrong, they can drastically reduce performance and fuel economy.

It’s no wonder that a major industry has sprung up to aid diesel owners in their wishes to eliminate some or all of these components.

Along with that, there’s the redneck infection, where small tuner computer interface devices are plugged into trucks to create billowing clouds of black smoke from the tailpipe, known as “rolling

coal” by the idiots that employ them.

These devices create extremely rich air-fuel mixtures that cause the particulate filters to quickly fail, so just about any truck that rolls coal has also had the filter bypassed.

If you’re thinking of bypassing any of your diesel’s emission controls, remember that that it’s highly illegal and the fines can be steep.

The chances of getting caught may be low, but the consequences are costly. Installing an exhaust pipe to eliminate the particulate filter can play havoc with the EGR system, and can create extreme exhaust-gas temperatures that can shorten the lifespan of the engine itself.

And, of course, getting rid

of the DEF system means you have to install a plug-in tuner chip, which fools the engine computer into thinking the DEF is still operational and so it keeps the engine running.

If you’re shopping for a pre-owned late-model diesel, especially from a private seller, never put your cash down until the emissions system is verified as fully operational.

Otherwise, you may be buying a ticking-time-bomb of a money pit. If you’re faced with the need to replace a particulate filter, consider having it power-cleaned first.

A filter replacement job can start at more than $2,500 and go up from there, while chemical power-cleaning services run less than $500.

With the increasing use of diesels by casual-commuting drivers in stop-and-start traffic, the number of plugged filters is on the rise. Frequent and regular highway driving can help keep them troublefree.

Take the time to understand how their self-cleaning systems work, and avoid interrupting an automatic regeneration cycle once it’s started.

During these periods, the engine’s computer will increase the amount of fuel injected, increasing the filter’s internal temperature to help burn off particles.

In the long run, there’s more to owning a diesel than just knowing which pump to use at the gas station.

123RF Bypassed diesel emission controls can lead to plenty of headaches and is something to be wary about when buying a used vehicle.