US EPA confirms widespread emission tampering in diesel pickups

27 November 2020

A report by the US Environmental Protection Agency’s Air Enforcement Division (AED) found that more than half a million diesel pickup trucks in the United States have been illegally tampered with their emission control systems. The AED analyzed evidence obtained by EPA civil enforcement personnel during many investigations conducted over approximately five years, involving tampering of Class 2b and 3 (GVWR of 8,500 - 14,000 lbs) diesel pickup trucks that occurred after 2009 and before 2020. The report appears to be the first-ever attempt—in the United States or elsewhere—to quantify the scale of tampering with vehicle emission systems.

For the cases that the EPA has investigated, the AED estimates that emission controls have been disabled or removed from more than 550,000 diesel pickup trucks in the last decade. These tampered trucks constitute approximately 15% of the national population of diesel trucks that were originally certified with emissions controls.

As a result of this tampering, more than 570,000 tons of excess NOx and 5,000 tons of PM will be emitted by these tampered trucks over the lifetime of the vehicles. Due to their severe excess NOx emissions, these trucks have an air quality impact equivalent to adding more than 9 million additional (compliant, non-tampered) diesel pickup trucks to the roads, the EPA said.

The most common types of aftermarket emission “defeat devices” are software files, known as “tunes”, and the hardware, known as “tuners”, used in tandem with the tunes to interface with and reprogram the vehicle’s original software to change the engine functions and calibrations. One example of an aftermarket defeat device is a delete tune. Delete tunes reprogram engine functions and override the OBD system so the tampered vehicle will operate without any diagnostic trouble codes (DTCs) or the “check engine” light—even though the vehicle’s aftertreatment systems may be partially or completely removed. Other common types of violations include hardware designed to physically defeat emissions controls, components to disable EGR systems (‘EGR delete’), and hollow “straight pipes” to replace the original emission aftertreatment devices (such as ‘DPF delete’ or ‘SCR delete’).

The EPA report reflects only tampering that involves the complete removal and disablement of emission controls hardware. This is known as a “full delete” of emissions controls that has the greatest impact on air quality. Other types of illegal tampering are common as well—such as installing tunes, but leaving emission controls hardware intact and operational.

Emissions from a diesel pickup truck increases drastically—tens or hundreds of times, depending on the pollutant—when its emissions controls are removed, the EPA said. Even when the filters and catalysts remain in the vehicle’s exhaust system, EPA testing has shown that using a tuner to recalibrate the engine can triple NOx emissions.

The findings of the report are based on 45 different delete tuning product lines manufactured by 28 different companies. The results exclude vehicles deleted using 12 other delete tuning product lines identified by the EPA, for which no data was available. The evidence gathered by EPA investigators includes information about the design and function of aftermarket parts, and sales records that show the overall volume of parts sold. EPA personnel obtained this evidence from civil investigative work, including on-site inspections, information requests, and interviews.

The report includes state- and county-level results based on a review of over 150,000 unique invoices containing delete tuning or hardware. These invoices cover sales of delete parts in all 50 states and approximately 83% of counties in the United States. The collected evidence also shows that approximately 50% of tampering occurs when vehicles are three years of age or less, and over 85% of tampering occurs by the time vehicles are eight years old.

The report focuses on delete tuners installed in Class 2b and 3 heavy pickup trucks, such as the Chevrolet Silverado and Dodge Ram 2500. However, such devices have been also installed in other types of vehicles. The EPA believes that this conduct occurs within most or all categories of vehicles and engines, including commercial trucks, passenger vehicles, pickup trucks, motorcycles, forestry equipment and agricultural equipment.

People tamper vehicles and engines for a variety of reasons. Some remove emissions controls to avoid the cost and time required to maintain emissions controls, while others tamper to increase fuel economy or power, or to customize their vehicle. Emission tampering devices are commonly available from many, usually smaller size, suppliers.

For many years, anti-tampering enforcement—in the USA and elsewhere—has been lackluster at best. More recently, the US EPA identified the stopping of aftermarket defeat devices for vehicles and engines as a high enforcement priority. In FY 2020, the EPA resolved 31 civil tampering and aftermarket defeat device cases that prevented more motor vehicle emissions than in any prior year in the agency’s history.

Source: New York Times | US EPA