Came back from Appleton wi and the HOE is giving me a P0420 ( catalyst system efficiency below threshold bank 1) and a secondary code is identical but pending ..
What is the issue?
Chi_town
CIRCUIT DESCRIPTION
In order to control emissions of Hydrocarbons (**), Carbon Monoxide (CO) and Oxides of Nitrogen
(NOx), The system uses a three-way catalytic converter. The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas, converting them into harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting it to nitrogen. The Vehicle Control Module
(VCM) has the capability to monitor this process using the HO2S (Bank 1, Sensor 1). The HO2S (Bank 1, Sensor 2), located in the exhaust stream past the three-way catalytic converter, produces an output signal which indicates the oxygen storage capacity of the catalyst; this in turn indicates the catalyst's ability to convert exhaust emissions effectively. If the catalyst is functioning correctly, the HO2S (Bank 1, Sensor 2) signal will be far less active than that produced by the HO2S (Bank 1, Sensor 1). If a problem exists which causes the VCM to detect an excessive HO2S (Bank 1, Sensor 2) activity outside of an acceptable range for an extended period of time, the VCM sets the DTC P0420. This DTC indicates that the three-way catalytic converter's oxygen storage capacity is below a threshold considered acceptable. This is a type A DTC.
