Review on 🚗 High-Quality Upstream and Downstream Oxygen Sensor Set for Chevy Malibu Equinox GMC Terrain Pontiac G6 Saturn Vue Sky (2.4L Engine Only) by Steve Beaumont

available My engine check was on, code P0420 (catalyst system below threshold) came up saying something was wrong with my emission which could have many reasons. After doing some research I started small, like replacing your oxygen sensors. I didn't know what the problem was, so I replaced both. In addition to the oxygen sensors, I recommend renting a tool (oxygen sensor socket, wrench) from AutoZone to save some more money when replacing the oxygen sensors. In any case, after some hardship (look for help on YouTube), I exchanged both lambda sensors (in front of the cat and one after). Code P0420 has not returned after 300 miles so far. So the new oxygen sensors are still working properly. I recommend this method first before thinking it is a catalyst.