Service Buddy
Fuel System

Code P0172

System Too Rich Bank 1

Plain English Meaning:Your engine is getting too much fuel

⚠️

Yellow: Drive with Caution

Running rich can damage catalytic converter

What You'll Notice (Symptoms)

  • Black smoke fuel smell poor MPG rough running

Most Common Causes

1Faulty injector high fuel pressure bad MAF

Verified 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

🛒 Parts for P0172 Repair

Common replacement parts for fuel system codes (Paid links)

MAF Sensor$30–$80
Fuel Filter$10–$30
Fuel Injector Cleaner$8–$15

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