DTC 4-3-5 Front Heated Oxygen Sensor Slow Response

4-3-5 FRONT HEATED OXYGEN SENSOR TOO SLOW

Preconditions for DTC
^ The ECM continuously monitors the time it takes for the Heated Oxygen Sensor (HO2S) to switch from rich to lean and back to rich again. If this time is too long, the control module interprets this as a fault in the front HO2S and DTC 4-3-5 is set.

Substitute value
^ Fuel trim shut off.

Fault sources
^ Uneven compression.
^ Air leakage in the intake system.
^ Air leakage in the exhaust system.
^ Incorrect fuel pressure.
^ Defective front HO2S.

Fault symptoms
^ May result in poorer performance.