How to Fix Toyota Rav4 P0420, check exhaust

Toyota Rav 4 P0420 engine code, the first thing to look for is an exhaust leak. It can sometimes be fixed cheap. Many people replace the O2 (oxygen sensor) when it is often an exhaust leak. I was able to fix this vehicle by fixing the exhaust leak near the front of the engine. It required two gaskets, Walker 31630 front gasket Walker 31374 rear gasket Walker 52592 (front centre pipe) #PO420