Following the need to reduce the emissions of internal combustion engines, many authorities began to impose limits for the pollutants, from these the idea of some guidelines defined as Conformity of Production (CoP) for on-road and off-road vehicles, respectively regulation R85 and R120. From here the description of the most common cycles used in the automated test cell of FPT Industrial, some of which were the NRTC and RMC for off-road (or non-road) vehicles, and WHTC and WHSC for on-road vehicles. The work presented was then a field analysis, aimed to solve the issues of the engines during the cell test, keep high the quality of the product and implement corrective action so that the problem would not occur again.