Review on 🔥 ECCPP Oxygen Sensor 234-4018 234-4012: Perfect Fit for Chevrolet/GMC 4.3L 4.8L 5.7L Models 96-02 - Heated O2 Sensor Upstream Downstream 4PCS by Aaron Ethridge

We have a 1998 Tahoe father/son project. I purchased all four O2 sensors, along with a few other items needed to test this truck's smog in California. Sensors appeared late in the project. I have two good quality OBD-II diagnostic tools (scanners) and both showed that only 3 out of 4 sensors were working. All four truck plugs have 11.92 to 11.99 volts for the sensor heaters. While the engine was warm and running in closed loop, both scanners show that only one sensor has a fluctuating signal voltage. Unfortunately the 30 day return window closed 5 days ago so we're sticking with them. Lesson learned: With the hassle involved in replacing them, I will never roll the dice at cheap O2 sensors again.