A single multiple gas sensor based on photoacoustic spectroscopy (PAS) technique for measurements in vehicle exhaust cylinders is reported in this work. This technique allows measurement of carbon dioxide and water vapor using a supercontinuum laser with a broad spectral output around the wavelength of 2 μm. The PAS sensor measures carbon dioxide and water vapor with a sensitivity of 10 ppmv in the 5–25% concentration range. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.