How can you lower the nox in your smog test?

Answer 1

NOx, or Oxides of Nitrogen, are formed during very high combustion temperatures. It needs to be reduced because NOx are green house gases. In an effort for auto manufacturers to reduce overall harmful exhaust emissions and to increase fuel efficiency, leaner fuel to air ratios have made NOx increase. Manufacturers curb its production by introducing exhaust gases back into the combustion chamber, thereby lowing combustion temperatures. Because eliminating all NOx is nearly impossible if the engine is running properly, manufactures install a last line of defense to clean the NOx out of the exhaust. This last line of defense is the 3-way catalytic converter. It uses semi-precious metals to absorb oxygen and then recombine the oxegen with the NOx to create harmless gases. If you are failing a smog test because of high NOx levels, the following thing need to be checked: 1st, make sure the engine is not overheating; 2nd, make sure the exhaust gas recirculation (EGR) system is functioning properly; 3rd, make sure the catalytic converter is functioning properly. You will probably need a professional mechanic who is adequately trained in emission repairs to perform these tests because they can be very difficult and require special tools. Any means to attempt to change the way the car runs to defeat the NOx test will most likely make the other gases, that previously passed, now fail. I have seen in some cases, when all else fails, put a new catalytic converter on the car, and temporarily it will allow you to pass the test.