Monitor Description
WARNING: This page is about a different car, the 2004 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
The air-fuel ratio (A/F) sensor varies its output voltage in proportion to the air-fuel ratio. Based on the output voltage, the ECM determines if the air-fuel ratio is RICH or LEAN and adjusts the stoichiometric air-fuel ratio. The ECM also checks the fuel injection volume compensation value to check if the A/F sensor is deteriorating or not. A/F sensor response deterioration is determined by the ratio of the A/F sensor output voltage variation and fuel trim variation