Fuel, Air Metering and Sensor Codes

Use live data, not the component name alone

Sensor circuit codes may describe low voltage, high voltage, an implausible signal or a slow response. Those conditions can come from the sensor, its wiring, its power supply or the system being measured. Fuel-trim codes also require context from short-term and long-term correction values.

A sensible first check

Inspect intake hoses and connectors, compare readings with a cold engine and then at operating temperature, and look for companion codes. Specifications differ by vehicle, so generic values should be treated as orientation rather than pass or fail limits.