Circuit/System Testing For DTC P0175
- Allow the engine to reach operating temperature. With the engine running, observe the affected Long Term FT parameter with a scan tool. The value should be more than -25 percent with the engine running at operating temperature.
- If the value is not more than -25 percent, inspect for the following:
- With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 19-42 kPa.
- Vacuum hoses for splits, kinks, and proper connections
- The inlet screen of the MAF sensor for blockage
- A malfunctioning MAF-Refer to DTC P0068 or P0121 or DTC P0101 or P1101 .
- The air duct for being collapsed or restricted
- The air filter for being dirty or restricted
- Objects blocking the throttle body
- Excessive fuel in the crankcase
- A saturated evaporative canister, a stuck purge valve, or the fuel cap not sealing
- The evaporative emissions control system for proper operation
- Excessive fuel pressure
- Properly functioning fuel injectors
- Fuel contamination
- The HO2S for proper installation and for electrical wires or connectors that may have contacted the exhaust system
- The HO2S signal circuit shorted to voltage