The exhaust emission characteristics of a 1969 Ford LTD equipped with a Marvel-Schebler LBG conversion were desired to supplement information on gaseous fuel vehicles. The car was equipped with a 429 cubic inch displacement engine, automatic transmission, and a decel device which held the throttle partially open on deceleration. The following tests were conducted: (1) standard 1968 Federal test procedure for exhaust emissions (FTP); (2) a closed, constant volume sampling technique using 9 repeats of the Federal emissions test cycle (CVS); (3) two closed, constant volume sampling technique using the LA4-S3 driving schedule as specified for 1972 and later testing. Bag samples were analyzed for carbon monoxide, carbon dioxide, hydrocarbons, and nitrogen oxides. It was concluded that the Marvel-Schebler car demonstrated the attainment of 1972 Federal standards and that the decel-device attached decreases hydrocarbon levels.