This research analyzes the emissions of oxides of nitrogen, NOx, emitted by an internal combustion engine, indirect injection multipoint Renault 1.8 L and its behavior in function of the values of lambda to suggest strategies of control of the oxygen content, with a better Functional sampling at the time, to the exhaust of the engine in order to mitigate the production of these toxic emissions. The analysis of the production of these emissions was done experimentally in an engine dynamometer where the engine was subjected to different conditions of load and revolutions to find the habitual behavior of a motor of a light vehicle before the information obtained by the Electronic Control Module From the monitoring performed by a conventional high and low oxygen probe. The study aims to focus the incidence of this type of monitoring on the production of NOx and to propose alternatives that offer a greater range of measurements offering advantages from the environmental point of view to a compound that has a high degree of toxicity and affectation on the respiratory system causing a significant increase in cases of lung cancer. Index Terms— NOx, lambda, dynamometer, oxygen sensor, ignition advance