Possible causes

– Faulty Rear Heated Oxygen Sensor Bank 2
– Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
– Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
– Inappropriate fuel pressure
– Faulty fuel injectors
– Intake air leaks
– Exhaust gas leaks

Tech notes

Replacing the Rear Heated Oxygen Sensor Bank 2 usually takes care of the problem.

When is the code detected?

The P0158 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)
– Possible higher than usual fuel consumption

P0158 Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

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P0158 Information for specific makes

P0158 ACURA
P0158 HONDA
P0158 BMW
P0158 CHRYSLER
P0158 DODGE
P0158 JEEP
P0158 FORD
P0158 HYUNDAI
P0158 INFINITI
P0158 NISSAN
P0158 KIA
P0158 LEXUS
P0158 SCION
P0158 TOYOTA
P0158 BUICK
P0158 MAZDA
P0158 MITSUBISHI
P0158 SUBARU
P0158 AUDI
P0158 VOLKSWAGEN
P0158 JAGUAR
P0158 CADILLAC
P0158 CHEVROLET
P0158 GMC
P0158 PONTIAC
P0158 SATURN