The intention of test group no. 6 was to evaluate the effect on exhaust emissions of disabling the heated air intake system. Ten vehicles were selected from the loaner fleet and were tested before and after disablement of the heated air intake system. No discernible difference was found between the before and after results. This result was attributed to the short period of time the heated air damper remained in the open position for the 'before disablement' test. Since all vehicles were cold soaked at a nominal temperature of 77 F, the temperature rapidly reached an operating temperature to close the damper. The intent of test group no. 8 was to provide test data to be used to evaluate the ability of various catalyst diagnostic tests to diagnose poisoned catalysts. The poisoning of the catalyst was accomplished by accumulating mileage using tankfuls of leaded fuel. After repeated tankfuls of leaded fuel were consumed, mileage was accumulated using tankfuls of unleaded fuel to provide data for evaluation of the rejuvenation process of the catalytic converter.