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P0172

Overview

Code

P0172

Code Type

P

Code Class

P0

System

Engine, Emissions

Severity Level

Medium

Emissions Related

true

Drivability Impact

Major

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0172 indicates that the engine is running too rich on Bank 1

Symptoms

Check Engine Light illuminated; Poor fuel economy; Black exhaust smoke

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

Rich air-fuel mixtures increase emissions and reduce fuel efficiency

Possible Causes

Faulty oxygen sensor; Leaking fuel injectors; High fuel pressure

Diagnostic Steps

1 Review fuel trim data; 2 Check for leaking injectors; 3 Measure fuel pressure; 4 Inspect oxygen sensor data; 5 Diagnose fuel control issues

Drive Safety Notes

Driving is possible, but continued rich operation may damage the catalytic converter

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