Tech Talk - The Dangers of Deletion

What does it mean to delete a truck and what are the potential problems one might incur by doing so? Before we dive into the pitfalls of deletion, let’s first take a look at the emissions systems and the purpose they serve.

For decades the automotive industry has had strict emissions guidelines on virtually all makes and models while the heavy truck industry wasn’t really affected by these regulations. For model years 2004-2006, the EPA’s new emissions standards were to reduce NOx emissions from highway engines to levels of 2.0g/bhp.hr. This was where the introduction of the exhaust gas recirculation system (EGR) to the trucking industry began. In 2007 the focus turned towards better diesel fuel itself. This is when low-sulfur diesel fuel came about with sulfur content dropping to 15ppm instead of the previous 500ppm. The reason behind the low sulfur fuel is that the sulfur is harmful to the diesel particulate filters (DPF) and the NOx catalysts that were required to meet EPA standards. 2010 is when big changes had to be made to get to .20g/bhp-hr for the NOx requirements. This brought about the selective catalytic reduction (SCR) and diesel exhaust fluid (DEF) emission systems. In 2013 it required OBD (on board diagnostics) for all on highway trucks. This system monitors emission systems and detects issues and recognizes faults which illuminates a warning lamp on the dash alerting the driver to seek an authorized repair facility. Since then, there have been several upgrades and changes to the emission systems to help reduce greenhouse gases, making for cleaner air and less pollutants across the board. With that, there are more changes coming for the 2024-2027 trucks as well which will put even cleaner burning engines on the road with the purpose of making a better environment for the next generation.

So why would someone delete this system from their truck? Simply put, these components can be costly to maintain and or replace if there is a failure. This can lead to unforeseen expenses and downtime for drivers. Ever since there have been laws for EPA standards, there have also been people that will gladly pay a “tuner” to make it so they can delete, or bypass, the emission system. This usually includes removing some, or all, of the components and installing a “tune” to the ECM to make the truck run correctly after parts are removed/bypassed. The cost of having someone delete your truck will be in the thousands of dollars and they all have waivers for you to sign because this is 100% illegal to tamper with or modify the emission system and that’s not a state-by-state law, it’s federal though state and local officials are there to uphold those laws. It also voids any manufacturer warranties on the after-treatment system as well as any other components or systems that are damaged as a result of the tampering.

It is also illegal for a dealer to perform any work on a deleted truck that is related to the aftertreatment, engine, electronic controls without first repairing the system back to the factory specs. This can cost upwards of $10-$20k depending on what is needed. The other part to this is the fact that the after-treatment system isn’t just there for emissions purposes. For instance, on a PACCAR MX engine certain “tuners” will also delete the EGR which cools down the combustion chamber. With this not functioning it can lead to overheating issues and cracked heads or even deeper issues. This is not just MX engines either, deleted ISX engines have noted VGT turbo failures and dropped liners. Almost all manufacturers have systems that are designed to work in conjunction with the after-treatment systems. So again, altering them can lead to expensive failures and extended downtime along with hefty fines.

Deleted trucks can also be difficult to sell and impossible to trade with any dealer. If you do sell or trade it without first informing the buyer of the changes made to the system, then there is legal actions that they are able to take against you. Even selling at an auction does not get you off the hook, as local law enforcement will often show up at these auctions to ensure tampering hasn’t occurred.

To summarize, deleting may sound like a good idea at first, and many companies that do these procedures will give you the song and dance about how great it is and that it won’t affect your truck, but the reality is that it’s much better to keep the truck “stock” and functioning as designed. There may be costs that incur under normal maintenance intervals, however they are much less expensive than a cracked cylinder head or damaged turbo, etc.

Some facts & details in this article were found in the article "The Cold Hard Truth on Truck Emission Deletes and Tunes" at diesellaptops.com/blogs