Review on 🔧 Enhanced Denso 234-4138 Oxygen Sensor for Optimal Performance by George Saunier

Terrible CEL (and VSC lights) came on and after furiously googling I needed a new A/F ratio sensor (because it's upstream, not an oxygen sensor). For less than $40, decided to try that first before considering a new catalytic converter and looking somewhere for a possible exhaust leak (both are entirely possible at 320,000 miles). After we unplugged the old A/F sensor (it took 20 minutes to get off the driver's side wheel well) and turned this baby on with a rental advanced auto parts oxygen removal tool and reset the CEL, we're back in business. Can be confirmed a few kilometers after installation, no more CEL. Now the car has resumed its regular shenanigans.