Catalytic convertor with Bank 1 &2

P0420 - Catalyst System Efficiency Below Threshold ( Bank # 1) Labor $100-125 Catalytic converter $500-600 (Front one) the rear rarely is bad. Don't accept the $2000 dollar offer,call check and confirm be wise ..Oh here's what it does: Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx → xO2 + N. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO. Oxidation of unburnt hydrocarbons (HC) to carbon dioxide and water: CxH2x+2 + [(3x+1)/2]O2 → xCO2 + (x+1)H2O..... A catalytic converter can also fail because of: Bad exhaust valves on the engine. Fouled plugs causing unburned fuel to overheat the converter