Graduation Semester and Year




Document Type


Degree Name

Master of Science in Civil Engineering


Civil Engineering

First Advisor

Melanie L Sattler


The research study objective was to find if there was any reduction in onboard exhaust emissions from a light duty passenger car (2007 Dodge Charger) with a Clean Air Catalytic Converter manufactured by Clean Air Associates, Inc. The research was conducted by the Civil and Environmental Engineering Department, University of Texas at Arlington as part of the North Central Texas Council of Governments Aftermarket Technology and Fuel Additive Research Program. Initially, emissions of pollutants were measured without the Clean Air Associates' retrofit device, called Baseline testing. A Horiba OBS-1300 On-Board System measured concentrations of the pollutants NOx, CO, CO2 and HC coming out of the tailpipe of the passenger car. The baseline data constituted 40 hours of on-road collection with 20 hours on arterial track and 20 hours on highway track for peak and off-peak hours of traffic. The retrofit device was then installed in the fuel line of the car. Emissions of the pollutants NOx, CO, CO2 and HC were measured on road with the device for 40 hours similar to the baseline data set. The device was removed after this session and 10 hours of post removal data was collected. The data collected was analyzed in grams per mile for each pollutant using Excel sheets. The average percentage increase/reduction in the concentration of the four pollutants from the baseline to 'with device' was computed and reported for highway and arterial test tracks. The following were the results of the data analysis: 1) The comparison of OBS 1300 accuracy values with the change in emission concentrations of each pollutant showed that the difference in emissions with and without the device exceeded the OBS 1300 accuracies for CO and CO2 arterial peak conditions and HC arterial off-peak conditions. 2) Overall, there is no significant difference in the four pollutant emissions after the installation of the device. 3) There was a 2.3% increase in fuel economy and on the highway and a 1.78% decrease in vehicle fuel economy with the installation of the device. 4) Dynamometer testing results were not very consistent with OBS 1300 testing results at 15 mph and 25 mph speed levels. 5) CO and CO2 emissions were lower in the post-removal case and exceeded the OBS accuracy limits. Conclusions were drawn based on the results and recommendations were made for future study for better evaluation of the retrofit device.


Civil and Environmental Engineering | Civil Engineering | Engineering


Degree granted by The University of Texas at Arlington