Subaru WRX P0405:  EGR Sensor “A” → Circuit Low

  P0405 is a generic OBDII trouble code.  It deals with the signal coming from the EGR system.  Since it is a generic code, it has the same meaning for the Subaru WRX as it would any other vehicle.   The EGR system allows a certain amount of the WRX’s exhaust to re-enter the combustion chamber, … Read more

Subaru WRX P0421 Code: Meaning, Causes, How to Fix

P0421 is a relatively rare OBDII trouble code.   It’s generic, which means it has the same definition for the Subaru WRX as it would any other vehicle. It is technically defined as “Warm Up Catalyst Efficiency → Below Threshold (Bank 1)”. In layman’s terms, it indicates that your Subaru WRX’s catalytic converter is not scrubbing pollutants efficiently … Read more

Subaru WRX P0316: Engine Misfire → At Startup

A relatively common, yet difficult to diagnose OBD-II trouble code is P0316. It has the same meaning for the Subaru WRX as it would any other vehicle.  It indicates that there is a misfire at the startup of the vehicle, and that it happens within the first 1000 revolutions of the engine. P0316: Engine Misfire … Read more

Subaru WRX P0740: Torque Converter Clutch Circuit Malfunction

P0740 is one of the most common transmission trouble codes. It means that the WRX‘s computer has detected that there is an issue with the torque converter clutch (TCC) solenoid circuit.     P0740: Torque Converter Clutch Circuit Malfunction   The TCC “locks” the drivetrain, which allows for a true mechanical connection between the transmission … Read more

Subaru WRX P0160: O2 Sensor → No Activity Detected B2S2

  P0160 is a standard OBDII trouble code. It has the same meaning for any vehicle with OBDII, including the Subaru WRX. When a vehicle has P0160, the PCM/ECM is not detecting any activity from the sensor.  It doesn’t mean that the O2 sensor isn’t getting power, but that the voltage isn’t changing, which is … Read more

Subaru WRX P0410: Secondary Air Injection System → Malfunction

P0410 is a generic OBDII trouble code.  This means that it has the same meaning for the Subaru WRX as it would any other vehicle.  It is letting you know that there is an issue with the secondary air injection system. P0410: Secondary Air Injection System → Malfunction  The secondary air injection system injects air … Read more