After showing you guys (and my class) the operation of an oxygen sensor on a motorcycle, I used this opportunity to discuss a very difficult topic from chapter 5 in my Engine Performance Diagnostics book. The topic is "Oxygen Sensor Bias Voltage".

An oxygen sensor slow response or low activity trouble code is almost always a faulty oxygen sensor. There are a few other things to consider before replacing the oxygen sensor.

In most cases, a slow response DTC gets fixed with oxygen sensor replacement.

Here’s part II of my wideband O2 case study. I cover some further voltage and current testing on this vehicle and go deeper into the operation of this type of wideband sensor.

In this first part of a two-part series, I get my hands dirty on a 2000 Lexus RX-300 with a wideband O2 sensor problem.

  1. Leaking Fuel Pressure Regulator (symptoms and testing)
  2. How to use Fuel Trim to identify the cause of a P0171 and P0174 code
  3. Using Fuel Trim to identify type of misfire (can it be done?)
  4. P0506 IAC System RPM below expected (vacuum leak) - Ford