P0172 or P0175

Allow the engine to reach operating temperature. With the engine running, observe the affected Long Term FT parameter with a scan tool. The reading should be between -22 and 0 percent.

• If not within the specified range, 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.
  • If the MAP sensor parameter is not between 19-42 kPa, refer to DTC P0106  and DTC P0107 or P0108 .
• Vacuum hoses for splits, kinks, and improper connections-Refer to Evaporative Emissions Hose Routing Diagram .
• 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-Refer to Crankcase Ventilation System Inspection/Diagnosis .
• The evaporative emissions control system for improper operation
• Excessive fuel pressure-Refer to Fuel System Diagnosis .
• Improperly functioning fuel injectors-Refer to Fuel Injector Diagnosis (W/CH47976) or Fuel Injector Diagnosis (W/J39021 or W/Tech 2) .
• Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
• 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