yes I know a little if you recycle the NOx production chemical reaction you'll reach what U expected,catalyst convertors are a way,in some old cars EGRs are other way but it does'nt exist in'new models specially for fuel injection systems!!!!
ok, thnks for all comments. of reference that I read, said that NOx will appear if the combustion temperature is more high / above 1000 degrees Celsius. but anyone who say that the nitrogen is inert gas (gas that can not be burned). is it possible we could reduce NOx by burning perfectly? or can only be reduced by maintaining combustion temperatures below 1000 degrees Celsius? please help....
burning in that situation is questioned not the specific burning process of nitrogen,if you search about harry scholl 's engine (cyclone engine) you'll find valuable things!!!