Control of the Exhaust Gas Tract Resistance of Modern Engines by the Run-Down Time during Testing

The toxicity standards of modern cars are constantly tightening. Such standards can be reached only when using special systems and assemblies. The existing diagnostic methods are too time-consuming and do not exclude possible multiple errors. The article proposes a method for diagnosing the ICE (internal combustion engine) exhaust system of cars by the run-down time in test modes. An active study of possible diagnostic parameters allowed us to identify a sensitive diagnostic parameter – the run-down time. As the resistance of the catalytic converter increases, the run-down time decreases significantly. The experimental test showed the following: 1) when the run-down starts from 5,000 rpm, the run-down time in case of reaching the limiting resistance of the catalyst is halved - from 4.8 to 2.4 s; 2) in case of a limiting change in the resistance of the catalytic converter from 34 to 10 mm in the exhaust gases, the O2 content increases from 2.53 to 4.92 %, the CO2 content decreases from 13.17 to 12.57 %, and there is a sharp decrease in CH from 100 to 8 ppm. The run-down parameters control range is from 15 to 0.1 s. The production test of the new method for diagnosing the ICE exhaust system showed its significant performance.