P0474 Subaru Exhaust Pressure Sensor Intermittent

Possible causes

– Faulty Exhaust Back Pressure Sensor
– Exhaust Back Pressure Sensor harness is open or shorted
– Exhaust Back Pressure Sensor circuit poor electrical connection

Tech description

Replacing the exhaust back pressure usually takes care of the problem

What about the obd code?

An Exhaust Back Pressure (EBP) signal that is detected out of range (high or low) by the Engine Control Module (ECM) will cause the engine to ignore the EBP signal and disable exhaust back pressure operation.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0474 Subaru Description

The Exhaust Back Pressure (EBP) sensor is a variable capacitance sensor that, when supplied with a 5-volt reference signal from the Engine Control Module (ECM), produces a linear analog voltage signal that indicates pressure.

The EBP sensor’s primary function is to measure exhaust back pressure so that the ECM can control the exhaust back pressure regulator (EPR) when needed.