EPA alleges that Respondent illegally sold and installed parts intended to defeat emission control devices on at least 96 occasions and failed to permit inspection and/or access to or copying of records in violation of the CAA. Selling defeat devices may result in significant increases in emissions of nitrogen oxides, particulate matter, and other pollutants that harm public health. Failure to allow inspection may cause significant harm by allowing instances of noncompliance to go undetected.