FixVault
Home › Kia › 2003 › Rio Base, Standard › Repair and Diagnosis › Engine Performance › System › Engine Controls - Self-Diagnostics › Diagnostic Tests › DTC P0133: Front Heated Oxygen Sensor Slow Response › Test Procedure

Test Procedure

  1. Turn ignition off. Connect Hi-Scan Pro/Kia Data Pro Scan tool or equivalent to OBD-II Data Link Connector. See Figure . Turn ignition on. Monitor for other DTCs. If DTCs related to misfire, Purge Control Solenoid Valve (PCSV), Mass Air Flow (MAF) sensor or HO2S heater are set, do all repairs associated with those DTCs before continuing with this procedure. If no other DTCs are set, go to next step.
  2. Start engine. Allow engine to idle. Thoroughly check exhaust system for leaks (primarily between Warm-up Catalytic Converter and front exhaust pipe). Also check intake system for vacuum leaks. If no exhaust or vacuum leak is found, go to next step. If exhaust or vacuum leak is found, repair as necessary. Go to step  6 .
  3. Turn ignition off. Release fuel pressure. See FUEL PRESSURE RELEASE - EXCEPT OPTIMA under FUEL SYSTEM - DELIVERY in SYSTEM & COMPONENT article. Install fuel pressure gauge at fuel rail. See FUEL PRESSURE (RIO) under FUEL SYSTEM - DELIVERY in SYSTEM & COMPONENT TESTING article. Fuel pressure should be 46-51 psi (320-350 kPa) @ idle. If fuel pressure is as specified, temporarily install a known good front HO2S and check for proper operation. If problem is corrected, replace HO2S. Go to step  6 . If fuel pressure is too high: go to next step. If fuel pressure is too low: go to step  5 .
  4. Turn ignition off. Release fuel pressure. SeeFUEL PRESSURE RELEASE - EXCEPT OPTIMA under FUEL SYSTEM - DELIVERY in SYSTEM & COMPONENT article. Disconnect fuel return line hose from fuel rail and blow through line towards fuel tank. If fuel return line is restricted, repair or replace as necessary. Go to step  6 . If return fuel line checks okay, replace fuel pressure regulator. Go to step  6 .
  5. With engine running, clamp fuel delivery line before fuel rail and check for fuel pressure to rise. If fuel pressure rises, replace fuel pump. Go to next step. If fuel pressure does not rises, check on-line fuel filter and fuel pump pick-up screen for restriction. If filters are okay replace fuel pump. Go to next step. If fuel filters are faulty, repair or replace as necessary. Go to next step.
  6. After repair, return vehicle to original condition. Clear codes using Hi-Scan Pro/Kia Data Pro Scan tool or equivalent. Verify repairs by driving vehicle and monitoring for pending codes. If DTC is set during test drive, follow appropriate DTC test procedure.
About FixVault