Exhaust Gas Analysis (petrol cars)

Emission is the most problem in all internal combustion engines, as they produce a lot of harmful gases which kills humans. Such gases as HC hydro-carbon, NOx nitrous-oxide, CO carbon-monoxide. Its a lot of systems been designed to control emissions such as EGR (exhaust gas recirculation valve) valve, oxygen sensor and catalytic converter. So emissions become a number one problem for planet earth, and that why a lot of manufactures trying to achieve best emissions for their vehicle and also starts to design alternative fuel engines, hybrids, electric, LPG and CNG.



Emission check on cold start, engine runs rich as it warms up.











Slightly wormed up but still in open loop.








Warmed up engine, very good result for 200.000 kms vehicle.








In this case O2 and CO2 high as one of the cylinders receive no fuel it just produce O2 and CO reacts with it and make CO2.









Rich engine condition.


The catalytic converter is very important part of emission control, as it passes through it they convert itself from harmful gases to harmless, the only disadvantage of it as it has to be very hot to work for 100% and usually vehicle need to travel for 5-7 kms before it starts to work. So if people travel for 15 kms to work and back it only works half of the trip. With more technology cats are installed as close as possible to the beginning of exhaust to reduce heating time, but they still need some time and that is a fact!
Another thing is an Oxygen sensor, the most simple one had only 1 wire-signal for ECU, but now they can be found with up to 5 wires, usually one would be signal, second sensor preheat and two grounds for optimal sensor signal and preheat. This sensor tells ECU when ever engine lean, rich or stoichiometric .