DTC P1170: Front Heated Oxygen Sensor, Inversion: Condition

DTC is set when Front Heated O2 Sensor (FHO2S) signal voltage remains more or less than .45 volt for 43 seconds after engine is started and has reached normal operating temperature. Engine speed must be more than 1500 RPM. Possible causes are:

• FHO2S.
• Fuel injector malfunction.
• Pressure regulator malfunction.
• Fuel pump malfunction
• Plugged or leaking fuel delivery hose and/or fuel filter.
• Plugged or leaking fuel return nose.
• Intake air system leaks.
• PCV valve malfunction.
• Purge solenoid valve malfunction.
• Purge solenoid hoses installed incorrectly.
• Ignition coil and igniter malfunction.
• Insufficient compression.
• MAF sensor malfunction.
• ECT sensor malfunction.
• TP sensor malfunction.
• EGR system malfunction (if equipped).
• Open or short circuit.
• Poor connection of PCM or FHO2S connectors.