Gas concentrations, under different engine operating conditions, different locations relative to the fuel spray are presented. The gas that is sampled is “snatched” from a continuous flow sampling probe. The time of snatching is controlled. The concentrations of CO, CO2, NOx, and O2 are plotted against, crank position. The sampled gases were analyzed for concentration in the as taken state and after the sampled gas had passed through a heated catalytic oxidation converter.Analysis have been performed and plots are presented of the findings. The analytic procedure developed for the data analysis are presented in detail.