Possible causes
– Faulty Rear Heated Oxygen Sensor Bank 1
– Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
– Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
– Intake air leaks
– Exhaust gas leaks
– Inappropriate fuel pressure
– Faulty fuel injectors
– Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
– Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
– Intake air leaks
– Exhaust gas leaks
– Inappropriate fuel pressure
– Faulty fuel injectors
Tech description
Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.
When is the obd code mean?
The P0138 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor signal voltage remains excessively high for an extended period of time.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– High Fuel Consumption
– Excessive Smoke from Exhaust
– High Fuel Consumption
– Excessive Smoke from Exhaust
P0138 LEXUS OBD Code Description