Identification

• O2 sensors measure the air-to-fuel ratios (AFR) in car engines and then deliver the measurement to the car computer. All o2 measurements are given in terms of how they compare to a baseline AFR of 14.7:1.
  
  

Comparisons

• Narrow-band o2 sensors are more limited than wide-band o2 sensors. For example, narrow-band o2 sensors can only send a signal to computers indicating whether the AFR is lower or higher than 14.7:1. Wide-band o2 sensors can tell the computer the amount by which the AFR is lower or higher than that baseline AFR.
  
  

Significance

• Car engineers and performance specialist prefer wide-band sensors when they need precise AFR readings. The more precise the reading, the better engineers can tune and tweak performance.