TorqueMech Beta
TorqueMech OBD Code Guide

P0172 - System Too Rich (Bank 1)

The engine is running rich on bank 1.

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Code Meaning

The engine is running rich on bank 1.

Common Causes

Leaking injector
Fuel pressure too high
Faulty MAF sensor
Faulty coolant temp sensor
Restricted air filter

Quick Checks

  • Check fuel trims (negative trims)
  • Inspect for leaking injector (smell, plugs)
  • Check fuel pressure/regulator
  • Verify ECT reading is realistic
  • Inspect air filter/intake

Likely Repairs

Use test results to confirm the fault before pricing the repair.

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Related Codes

P0171
System Too Lean (Bank 1)
Open ->
P0174
System Too Lean (Bank 2)
Open ->
P0175
System Too Rich (Bank 2)
Open ->

Next Steps

Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.

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