With a dirty air filter, a lack of scheduled oil changes, severe driving conditions, poor fuel, and short trips, you
have the makings for an inefficient catalytic converter. Eventually a combination of these conditions can
increase carbon accumulation in the combustion chamber leading to higher combustion temperatures
and compression ratios. The result is excessive NOx output by the engine.
Combine excessive NOx output with carbon fouling of the spark plugs and O2 sensors, the contamination or fouling of the catalytic converter and you have the ingredients for an emissions system failure. In short, the catalyzing metals in the converter are no longer exposed to the exhaust gases, and the converter is rendered inactive. The deactivation of the catalytic converter causes a reduction of O2 storage which is detected by the O2 sensor resulting in a PO420 diagnostic trouble code.
We at Converter Warehouse can help you diagnose problems...just give us a call at 888-240-7088 and we'll be glad to help!!!