SAE J2012 / ISO 15031-6 · powertrain

P0174: Sistema muito pobre — mistura magra (Banco 2)

Sistema muito pobre — mistura magra (Banco 2): Excessive positive fuel trim correction on Bank 2 cylinder bank.

P0174 — Diagnostic Summary
Trouble Code (DTC)P0174
Official SAE DefinitionSistema muito pobre — mistura magra (Banco 2)
Vehicle Subsystempowertrain
Driving SeverityMEDIUM

Observable Symptoms

  • Rough idle
  • Hesitation under load
  • MIL illuminated

Most Probable Root Causes

  • Intake plenum or vacuum leak affecting Bank 2
  • Contaminated MAF sensor
  • Weak fuel pump or clogged Bank 2 injectors

Step-by-Step Diagnostic Procedure

  1. Compare Bank 1 and Bank 2 LTFT values at idle and 2,500 RPM
  2. Inspect intake boots and PCV breather lines
  3. Measure fuel rail pressure under load