Service Buddy
Fuel System

Code P0172

System Too Rich Bank 1

Plain English Meaning:Your engine is getting too much fuel

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Yellow: Drive with Caution

Running rich can damage catalytic converter

P0172 Symptoms

  • Black smoke fuel smell poor MPG rough running

Most Common Causes of P0172

1Faulty injector high fuel pressure bad MAF

P0172 Repair Playbook

Required Mechanic Tests

A qualified shop should perform these tests before replacing any parts to ensure they aren't guessing:

O2 sensor readings fuel trim check injector test

Typical Fix Paths & Estimated Costs

Injector repair MAF cleaning $150–$800

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Parts for P0172 Repair

Common replacement parts for fuel system codes. (Paid links)

MAF Sensor
$30–$80 · Est. Price
Fuel Filter
$10–$30 · Est. Price
Fuel Injector Cleaner
$8–$15 · Est. Price

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