Discover the overlooked software, electrical, and systemic engine failures that prevent a permanent fix. Check engine light can still be on after changing the o2 sensor because the codes require removal, you replaced the wrong oxygen sensor, and the engine light. I have often seen biased upstream afr sensors cause downstream sensor codes on toyota, ideally you need to graph all 4 sensors on a scan tool and see what they are doing.
Tacoma O2 Oxygen Sensor; Upstream (05-08 4.0L Tacoma) - Free Shipping
After replacing the o2 sensor, tightened it, plugged the new sensor in, & clearing the code with the torque app, the light came back on again after a day.
If your oxygen sensor codes keep coming back after you replaced the sensor, it’s highly probable your o2 sensor wasn’t at fault to begin with
If you have replaced your oxygen sensor and the light is still on, it is possible that there is a problem with the wiring or connector If you’ve replaced your o2 sensor and are still getting a code, it’s possible that the problem isn’t with the sensor itself Instead, there could be an. That code is fuel system lean bank 2, typically it's not the afr/o2 sensor but a fuel or air metering issue
I would want to look at long and short term fuel trims on both banks at idle and while. How to fix when oxygen sensor codes keep coming back after replacement of the o2 sensor 5 mistakes everyone makes when fixing o2.
