Diagnosing a Failed Emissions Test – High HC, CO and NOx Causes and Repairs – YouTube

In this video I go over how you can diagnose excessive amounts of Hydro Carbons (HC), Carbon Monoxide (CO) and Nitrogen Oxide (Nox) in your exhaust. I go over how a rich or lean condition can cause one or more of these gases to be high and therefore causing you to fail emissions. Also I go over some components like the Catalytic Converter, Oxygen Sensor (O2), Ignition Coils, Spark Plug Wires, Spark Plugs, EGR Valve, which are part of your emissions systems on your car and how they effect different levels of each gas.