Engine-Codes - Saturn - P0172 SATURN

P0172 SATURN - Fuel Trim System Rich Bank 1

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P0172 SATURN Possible Causes

  • Faulty Front Heated Oxygen Sensor
  • Faulty Spark Plugs
  • Faulty Mass Air Flow (MAF) sensor
  • Exhaust Gas Leaks
  • Ignition Misfiring
  • Incorrect Fuel Pressure
  • Faulty Fuel Injectors

How is the P0172 SATURN code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Tech Notes

There are Factory Service Bulletins for the following Saturn models:

2000-2008 Saturn All Models
2000-2008 Saturn Factory Service Bulletin OBDII Code P0172

2000 Saturn L-Series
2001 Saturn L-Series
2002 Saturn L-Series
2003 Saturn L-Series
2000-2003 Saturn L-Series Factory Service Bulletin OBDII Code P0172

What is the cost to diagnose the P0172 SATURN code

Labor: 1.0

The cost to diagnose the P0172 SATURN code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
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When is the code detected?

- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too large. (The mixture ratio is too rich.)

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Excessive Fuel Consumption

P0172 SATURN Meaning

The Engine Control Module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open Loop and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without heated oxygen sensor (HO2S) input. During Closed Loop, the ECM adds HO2S inputs to calculate the short and long term fuel trim (FT) adjustments. If the HO2S indicates a lean condition, the fuel trim values will be above 0 percent. If the HO2S indicates a rich condition, the FT values will be below 0 percent. The short term FT values change rapidly in response to the HO2S voltage signals. The long term FT makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1.

More Information

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