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Diagnose/P3377
P3377Medium SeverityEmissions

Advanced catalyst/exhaust monitoring Code 77

What This Means

This code indicates the advanced catalyst/exhaust monitoring system has detected an abnormal operating condition. Code P3377 monitors cylinder management and exhaust aftertreatment components.

Common Symptoms

  • Check engine light on
  • Performance concern
  • Emissions issue
  • Engine management change

Common Causes

  • Component degradation
  • Sensor failure
  • Actuator malfunction
  • System contamination
  • PCM monitoring issue

Estimated Repair Cost

$175 – $1000
Parts and labor (varies by vehicle and location)
Difficulty:Moderate

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For informational purposes only. Diagnostic trouble codes are starting points for diagnosis, not definitive answers. Always consult a certified mechanic for proper diagnosis and repair. Estimated costs vary by vehicle, location, and shop rates.