2019 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE

Drive Cycle A

DTC Item Condition Number of driving cycles on the detecting condition
P0030 A/F/O2 HEATER CONTROL CIRCUIT BANK 1 SENSOR 1 - 2
P0087 FUEL RAIL/SYSTEM PRESSURE - TOO LOW BANK 1 Complete diagnosis with drive cycle B as well. 1
P0088 FUEL RAIL/SYSTEM PRESSURE - TOO HIGH BANK 1 Complete diagnosis with drive cycle B as well. 1
P0128 COOLANT THERMOSTAT (ENGINE COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE) - 2
P013A O2 SENSOR SLOW RESPONSE - RICH TO LEAN BANK 1 SENSOR 2 - 2
P013B O2 SENSOR SLOW RESPONSE - LEAN TO RICH BANK 1 SENSOR 2 - 2
P0141 O2 SENSOR HEATER CIRCUIT BANK 1 SENSOR 2 - 2
P014C A/F/O2 SENSOR SLOW RESPONSE - RICH TO LEAN BANK 1 SENSOR 1 - 2
P014D A/F/O2 SENSOR SLOW RESPONSE - LEAN TO RICH BANK 1 SENSOR 1 - 2
P015A A/F/O2 SENSOR DELAYED RESPONSE - RICH TO LEAN BANK 1 SENSOR 1 - 2
P015B A/F/O2 SENSOR DELAYED RESPONSE - LEAN TO RICH BANK 1 SENSOR 1 - 2
P0171 SYSTEM TOO LEAN BANK 1 Complete diagnosis with drive cycle B as well. 2
P0172 SYSTEM TOO RICH BANK 1 Complete diagnosis with drive cycle B as well. 2
P0300 RANDOM/MULTIPLE CYLINDER MISFIRE DETECTED Complete diagnosis with drive cycle B as well. 2
P0301 CYLINDER 1 MISFIRE DETECTED Complete diagnosis with drive cycle B as well. 2
P0302 CYLINDER 2 MISFIRE DETECTED Complete diagnosis with drive cycle B as well. 2
P0303 CYLINDER 3 MISFIRE DETECTED Complete diagnosis with drive cycle B as well. 2
P0304 CYLINDER 4 MISFIRE DETECTED Complete diagnosis with drive cycle B as well. 2
P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK 1 - 2
P0459 EVAP SYSTEM (CPC) PURGE CONTROL VALVE "A" CIRCUIT HIGH - 2
P1191 FUEL RAIL PRESSURE SENSOR "A" CIRCUIT NO ACTIVITY DETECTED Complete diagnosis with drive cycle B as well. 2
P2096 POST CATALYST FUEL TRIM SYSTEM TOO LEAN BANK 1 Complete diagnosis with drive cycle B as well. 2
P2097 POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1 Complete diagnosis with drive cycle B as well. 2
P2195 A/F/O2 SENSOR SIGNAL BIASED/STUCK LEAN BANK 1 SENSOR 1 - 2
P2196 A/F/O2 SENSOR SIGNAL BIASED/STUCK RICH BANK 1 SENSOR 1 - 2
P226B TURBOCHARGER/SUPERCHARGER BOOST PRESSURE TOO HIGH - MECHANICAL - 1
P2270 O2 SENSOR SIGNAL BIASED/STUCK LEAN BANK 1 SENSOR 2 - 2
P2271 O2 SENSOR SIGNAL BIASED/STUCK RICH BANK 1 SENSOR 2 - 2
  1. Drive for 20 minutes or more at a constant speed of 80 km/h (50 MPH) or more.
  2. Stop the vehicle and idle for one minute.
  3. Read the temporary code using the Subaru Select Monitor or general scan tool. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>READ DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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