2013 Malibu P0420 Code - Try this first!

Our 2013 Malibu with 130k miles is starting to have some issues. One is a long standing CEL that shows P0420 -Catalyst System Efficiency Below Threshold Bank 1 - and according to my research the possible causes are a defective catalytic converter or a bad downstream O2 sensor. Guess what Im replacing first... #chevymalibu #diy #fixmyjunk Special thanks to Patrons- DizTraveler and Anonymous. Thank you for your support! Patreon - https://www.patreon.com/user?u=30404497 PayPal - https://www.paypal.com/paypalme2/dzlf... Amazon Affiliate Links Upstream O2 sensor - https://amzn.to/2zt69jK Downstream O2 sensor - https://amzn.to/2Y1XAGT LAUNCH OBD2 Scanner CRP123 - https://amzn.to/2x6pMgB Gear I use GoPro Hero 7 Black - https://amzn.to/2YpJEUU GoPro Charger w/extra battery - https://amzn.to/2HGvTvL 64GB Sandisk Extreme SD card - https://amzn.to/2UY7dlA Puluz Aluminum Cage for GoPro - https://amzn.to/2HG6Jxw Movo VXR10GY directional microphone - https://amzn.to/2TAc4YL GoPro Microphone Adapter - https://amzn.to/2YpKgtG Sabrent Flexible Tripod - https://amzn.to/2HQHXtA Zomei Pro 0.42 wide angle lens for smartphones - https://amzn.to/2HI33LE DJI Spark drone w/Remote - https://amzn.to/2Yq1g32 DJI Spark Drone w/Flymore option -https://amzn.to/2uCT7u9 mkdvojnqpfoivnoqerig-019834utpo134ngwrtin9248hg92