A gas analysis system is described which is composed of a Fourier transform infrared spectrometer, a quadrupole mass spectrometer, and a total hydrocarbon analyzer. This combination of instrumentation along with a unique sampling system allows on-line analysis of regulated and non-regulated emissions. Data are presented demonstrating the system's capability for analysis of regulated and non-regulated emissions from catalyzed and non-calatyzed exhaust. To demonstrate the accuracy of the analysis system, both oxygen and carbon mass balance data are given for an experiment involving the three/way catalysis of a steady-state gas stream synthesized to resemble the exhaust from a gasohol fueled engine. The use of these techniques for the analysis of vehicle emissions is also demonstrated.