The article presents the results of toxic emissions in road tests of an urban bus. The object of the study was the Mercedes Connecto city bus. The results of toxic emissions were recorded in real time while bus drives with the use of the Semtech Ecostar exhaust gas analysis system. The study involved a planned bus SORT 2 test cycle. During the tests, the fuel consumption and exhaust gases such as CO2, CO, NOx, HC, NMHC, and O2 were recorded. The driving conditions in the study were constant (test cycles took place at the airport), exhaust gas temperature (hot engine) was also constant, etc. The results were based on average values from 5 test cycles for each test. The influence of electric load in the bus grid on the level of toxic emissions was measured. It has been proven that fuel consumption and CO2 emissions increased, which means a change in the value of components of toxic emissions. This fact evident from the increased CO emissions and decreased O2 emissions. Logically, the air-fuel mixture may have been enriched due to the increased demand for effective power generated by the engine crankshaft.