Can you get in trouble for deleting DEF system?

Well, let’s just get this out of the way right now. It’s illegal to remove it. Yes, it can be done and there are thousands of trucks on the road today that have had all emissions disabled or removed with seemingly no repercussions.  There is, however, several reasons why (besides the illegal part) a person would want to leave the emissions systems intact on their diesel vehicle. Let’s start with a little history of why “deletes” became such a common practice to begin with.

In mid-year 2007, all vehicle manufacturers were required to meet the new, more stringent tail pipe emissions standards. For diesels this meant much lower NOX and particulate emissions were mandated. In order to meet these restrictions new emissions reducing systems were put in place. These systems included exhaust gas recirculation (EGR), diesel particulate filters (DPF), and varying methods of NOX (nitrogen dioxide) reduction. Reducing NOX was done mostly with a combination of cooled EGR and a post engine (in the exhaust) methods of trapping or converting NOX into harmless emissions.

As with any newly implemented technology there was a steep learning curve for both manufacturers and vehicle owners/operators. To be honest, the first generation of vehicles with these systems were problematic. In a lot of cases, the problems were so severe the vehicles were not usable a good portion of the time. When it comes to needing a reliable vehicle to earn a living, this was a very big problem.

A lot of the problems which occurred were due to the operating characteristics of these newer vehicles. It was no longer acceptable to start your truck and let it idle until its warm, then drive 5 miles (ca. 8 km) to your job site where it may spend a good portion of the day making short trips and idling. While this was a standard practice for decades, the new engines carboned up heavily, the DPF would plug, sensors would fail, and the truck would become useless. These trucks needed to be driven, and worked hard, to burn out soot accumulated in the DPF. To make problems worse, repairs were exceptionally expensive, and warranty did not always cover what was considered to be operator error.

This is where removing the emissions equipment started to gain popularity. Why spend $3000-$5000 to replace a diesel particulate filter when it can be removed for less than $1000? What’s the downside to improved reliability, better fuel economy, and a little more power? It’s easy to see why “deletes” gained so much popularity in this time frame. Most people just wanted their truck to be as reliable as a hammer, like the diesels of old. And it was relatively cheap and easy to defeat the emissions devices. Just buy one of the many readily available plug-in tuners, download software into the ECM, and remove the troublesome components from the truck. There, problem solved!

As we soon found out, doing this was just a band-aid, and created some unintended problems.

The beginning of the end…

Circa 2013 the EPA began in earnest its crack down on emissions defeat devices. Several larger companies which sold the readily available “box” tuners were hit with fines and ordered to cease manufacturing and selling these products.  And so began the steady decline in readily available emissions defeat devices. Custom tuning became the required means of removing the emissions equipment, but even that has become increasingly difficult and expensive to purchase.

The good news is, around this time frame the second and third generations of emissions equipped vehicles were rolling out. A lot of the kinks were worked out by this time, making the trucks much more reliable. Still, the perceived “need” to delete brand-new trucks persisted.

A few months ago, the EPA announced that they will be focusing more on stopping the manufacture and use of emissions defeat devices in 2020 and beyond. Not only are they going after tuners, parts manufacturers and shops, but the chances of end users being ticketed are also increasing. Which brings me to the focus of this article, the best reasons to NOT remove your vehicles emissions equipment.

1. IT’S ILLEGAL. That really should be enough right there.
2. It WILL void your factory warranty, no question about it. Most dealers today will not even work on a vehicle that has had the emissions equipment tampered with or removed. Stories of dealers wanting to either return the vehicle to stock or having the customer tow it out of the shop are more and more common. With repair costs running into the $15000+ range for an engine failure, why risk losing warranty over the possibility of the emissions equipment failing?
3. The reliability is questionable. You are trading a well-engineered, technologically advanced, full vehicle integrated system, for tuning done by somebody you assume knows what they are doing. Head gasket failures are more common with delete tuning and can cost upwards of $8000 to repair. Blindly trusting someone with your $20,000 engine seems like a big gamble when you put it in the correct context. Don’t get me wrong, there are MANY highly qualified tuners out there that do it correctly and whom we trust. But for everyone who does it right, there are many who don’t. Years of experience and hundreds of vehicles with tuning related problems have proven that fact for our shop alone.
4. Repairs may become more expensive when needed. “Say what? More expensive?” Let me tell you why. When the emissions defeat tuning is installed in the ECM, many of the OEM diagnostic protocols are removed or modified to keep the engine running normally. If the equipment was just removed without tuning, the engine would go into a limp mode at least, or in many cases it will not be allowed to start. That’s all fine and dandy until something goes wrong and diagnostics must be done. All of those diagnostic protocols that were there to, in part, aid in quick diagnosis and repairs are gone. Without them the technician’s job just got harder, which means more labor, and more money out of your pocket. Some aftermarket software will not even allow OEM scan tools to connect to the vehicle.
5. Resale or trade in value will likely drop. It is becoming more common for dealers to not take deleted trucks in trade, because they are not able to resale them. They either will be sent to auction, or the vehicle will need to be returned to stock. Returning the vehicle to stock can cost up to $10,000. It’s easy to see the problem there.
6. The vehicle will not pass inspection. If you are required to have your vehicle smog checked, or have DOT inspections done, it will not pass. In some cases, you will not be able to drive the vehicle until it is returned to original specifications and it passes inspection. If you use the vehicle to earn a living, out-of-pocket costs and downtime will add up quickly.
7. If properly maintained, the emission system should last the life of the vehicle. “What’s that you say? It can be reliable?” Why yes, yes it can. The DPF was designed in most cases to exceed 150,000 miles (ca. 241,402 km) life expectancy. It is not uncommon to see 250,000+ miles before replacement. Some other components may need replaced or serviced in that time frame. Usually though, it’s just a sensor or minor component that is hundreds of dollars and will last another 100k miles. If you follow the manufacturer recommended service schedule and operating recommendations, chances are there will be minimal problems. Read the operators manual, learn how these modern diesels differ from your 1985 VW Rabbit, and try to operate the vehicle within the recommendations.
8. Your truck won’t “roll coal”. “Wait, that’s a reason to NOT delete my truck?!” Yes, yes, it is. Rolling coal was so 2017. But really, why waste fuel and try to burn down your engine? It’s not as cool as some people think, and I’ll let you in on a secret: You don’t need to roll coal to make horsepower. It’s just a sign of an inefficient setup. Off the factory floor these trucks are pushing 400+ horsepower. And yes, even with the DPF on, a drive able 550+ RWHP is possible with just tuning!

There are more reasons, but these few are the ones we run into on a regular basis. We understand the concerns of our customers when it comes to reliability, but we can assure you that in MOST cases modern, emissions equipped diesel vehicles are perfectly reliable without removing any emissions related equipment. They all also perform well and are more than capable of what 99.99999% of us need them for.

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