A sensitive laser mass spectrometer is being developed for fast multicomponent engine exhaust analyses. The features of the system meet the requirements of the analysis problems at dynamic motor test stands: detection of all organic and inorganic exhaust constituents of concentrations higher than 1 ppm simultaneous detection of up to 12 selectable exhaust compounds with 100 Hz repetition rate 2 millisecond time precision relative to the motor phase. precise sampling location everywhere in the exhaust pipe system, e.g. single valve or cylinder exhaust gas analysis ruggedness for operation at engine test facilities The time and space resolution allows the tracking of the different exhaust components during one and more motor cycle in static and transient engine operations. This information is essential for an understanding of the combustion processes, which is necessary for the development of the engine and engine control and other efforts to reduce emission of pollutants.First measurements at motor test facilities proved the proper functioning of the system and show results in particular about the motor load and revolution dependent aromatic hydrocarbon emissions.