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The classical approach to prepare engine exhaust emissions control systems for evaluation and certification is to condition the fresh parts by aging the systems on an engine/dynamometer aging stand. For diesel systems this can be a very lengthy process since the estimated service life of the emissions control systems can be several hundred thousand miles. Thus full useful life aging can take thousands of engine bench aging hours, even at elevated temperatures, making aging a considerable cost and time investment. Compared to gasoline engines, diesel engines operate with very low exhaust gas temperatures. One of the major sources of catalyst deactivation is exposure to high temperature [ 1 ].

A computer controlled system capable of intercepting and performing closed-loop control of a vehicle subsystem during targeted modes of operation was developed. The system has been given the acronym ERIC, for Emissions Reduction Intercept and Control system. This study was prompted by the need for the ability to modify engine controls through targeted modes of operation, without altering the majority of engine operation, to assist in the integration of exhaust aftertreatment and engine systems. The general concept and approach for applying the ERIC method, and application of the system to perform targeted, mode-activated EGR control intercept on a 1997 Ford Crown Victoria, are described in this paper. Data are presented that demonstrate how the problem mode was identified, targeted, mapped, and modified. FTP-75 test data are presented to show the impact of this particular application.

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.