Search Results

A program to demonstrate the performance of advanced emission control systems in light of the California LEV II light-duty vehicle standards and the EPA's consideration of Tier II emission standards was conducted. Two passenger cars and one light-duty pick-up truck were selected for testing, modification, and emission system performance tuning. All vehicles were 1997 Federal Tier I compliant. The advanced emission control technologies evaluated in this program included advanced three-way catalysts, high cell density substrates, and advanced thermally insulated exhaust components. Using these engine-aged advanced emission control technologies and modified stock engine control strategies (control modifications were made using an ERIC computer intercept/control system), each of the three test vehicles demonstrated FTP emission levels below the proposed California LEV II 193,000 km (120,000 mile) ULEV levels.

A non-thermal plasma treatment of diesel engine exhaust was effective in removing particulate (soot) and oxides of nitrogen (NOx) from two different light-duty diesel vehicles: an older-technology indirect-injection Toyota truck, and a newer-technology direct-injection Dodge truck. Particulate removal efficiencies and NOx conversion efficiencies were determined at space velocities up to 20,000/hr. Particulate removal efficiencies were above 60 percent for most conditions, but decreased with increasing space velocities. Conversion efficiencies for NOx and carbon monoxide (CO) were also dependent on the space velocity. The NOx conversion efficiencies were generally greater than 40 percent at space velocities less than 7000/hr. The CO concentration increased through the plasma reaction bed indicating that CO was produced by reactions in the plasma.