Diagnostic Aids

A DTC P0130 is more likely to set during city driving. Avoid operating vehicle on the highway when validating a DTC P0130.

Scan tool output control feature, Fuel Injector Modification, can be used at idle to check oxygen sensor performance. Increasing Fuel Injector Modification Commanded State to 25 percent should cause HO2S 1 voltage to exceed 800 mV. Decreasing Fuel Injector Modification Commanded State to - 12 percent should cause HO2S 1 voltage to drop to less than 100 mV. An oxygen sensor that fails to respond accordingly may be faulty or contaminated. When performing a Fuel Injector Modification using a scan tool, loop status will remain open loop and short term FT will be fixed at zero percent.

If a DTC P0130 is intermittent, driving vehicle under the conditions outlined in INSPECTION/MAINTENANCE PROCEDURES, can verify whether the fault is present. See INSPECTION/MAINTENANCE HEATED OXYGEN SENSOR/OXYGEN SENSOR (HO2S/O2S) SYSTEM SET PROCEDURE  under INSPECTION/MAINTENANCE PROCEDURES. Check for any of the following conditions:

• Misrouted heated oxygen sensor wiring. The sensor pigtail may be misrouted and contacting exhaust system causing a short to ground.
• Verify PCM to engine electrical grounds are okay.
• An incorrect fuel pressure. Fuel system can go lean if fuel pressure is too low and DTC P0130 may be set. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 1.8L VIBE article.
• An incorrectly calibrated fuel injector.
• Any vacuum leaks. Check for disconnected or damaged vacuum hoses and for vacuum leaks at intake manifold, throttle body, and crankcase ventilation system.
• Any exhaust leaks near the HO2S. An exhaust leak may cause outside air to be pulled into the exhaust gas stream and past the HO2S. Outside air may cause DTC P0130 to set.
• A shorted HO2S. A HO2S that is shorted to ground will display less than 0.1 volt on scan tool. An HO2S that is shorted to voltage will display a reading of more than 1.0 volt on scan tool. Water contamination of HO2S can cause a low or high HO2S voltage to be indicated. A DTC P0130 that occurs more frequently when driving through standing water or when operating vehicle in wet driving conditions can indicate water intrusion. Replace HO2S if sensor is adversely affected by moisture.
• A contaminated HO2S. Silicone contamination of HO2S can cause a low signal voltage to be indicated. Silicone contamination is indicated by a powdery white deposit on the portion of HO2S exposed to the exhaust stream. Before replacing the HO2S, determine the cause of contamination and correct the condition.
• Fuel contamination. Small amounts of water can be delivered to fuel injectors and cause a lean exhaust indication. A lean exhaust indication can also be caused by too much alcohol in the fuel.
• A faulty electrical connection to the PCM.
• A saturated Evaporative Emission (EVAP) canister or a faulty EVAP purge control. SeeEMISSION SYSTEMS & SUBSYSTEMS in SYSTEM & COMPONENT TESTING - 1.8L VIBE article.

An intermittent malfunction may be caused by a fault in the HO2S 1 electrical circuit. Check wiring harness and components for an intermittent condition. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 1.8L VIBE article. Repair any electrical circuit faults that were found. The information included in freeze frame data can be useful in determining the vehicle operating conditions when the DTC first set.