SACRAMENTO –Truck manufacturer Navistar Inc. has paid $2 million to resolve allegations that it altered heavy-duty vehicle engines from their certified design, potentially causing excess diesel emissions and negatively impacting air quality.

The Illinois-based company modified its vehicle calibrations from their certified design through “running changes” in the engines of its heavy-duty trucks without notifying the California Air Resources Board that the changes were being made, as is required. The undocumented running changes were implemented on new vehicles in production and were also deployed to post-production vehicles in the field. An undocumented running change is an unauthorized change to a previously approved engine design, and is considered a violation because of its potential to affect engine performance leading to increases in smog-forming and toxic emissions. The violations were discovered during routine engine testing by CARB.

“Engine modifications are allowed when they are disclosed up front and fully evaluated to confirm there are no negative emissions impacts,” said CARB Executive Officer Richard W. Corey. “These design changes by Navistar differed significantly from what was approved for sale. The high penalty reflects how seriously we take this type of activity and underscores that efforts to circumvent the rules will be discovered and never end well for the manufacturers.”

The company was cooperative throughout CARB’s investigation and agreed to pay $1,013,400 (50%) to the Air Pollution Control Fund to support air quality research. The remaining half will be paid to the South Coast Air Quality Management District and will be used to install and maintain high-performance air filtration systems in Southern California schools, especially those located in disadvantaged communities disproportionately impacted by air pollution.

Diesel exhaust contains a variety of harmful gases and more than 40 other known cancer-causing compounds. In 1998, California identified diesel particulate matter as a toxic air contaminant based on its potential to cause cancer, premature death and other health problems.

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