Details

• Brand:

  

• SKU:

  12559850

• Positions: Left Front, Left Rear, Right Front, Right Rear, Rear Front, Rear
• Other Names:

  Oxygen Sensor, 787

• Description:
  • Heated oxygen sensor (O2 sensor)
  • Used in the engine exhaust system to monitor oxygen levels and adjust fuel mixture
  • Often called:
    • Front O2 sensor
    • Upstream oxygen sensor

  Example OEM part

  GM 12559850 Heated Oxygen Sensor

  What it does

  • Measures oxygen content in exhaust gases
  • Sends voltage signal to the ECU
  • Helps maintain the ideal 14.7:1 air/fuel ratio for efficiency and emissions

  Where it’s used

  • Typically mounted in the exhaust manifold or pipe before the catalytic converter
  • Found on many early-2000s GM vehicles like:
    • Chevy Impala / Monte Carlo
    • Buick Century / Regal
    • Cadillac DeVille / Seville
    • Chevy Blazer, S10, etc.

  Quick takeaway

  • 11504611 = bolt
  • 12559850 = oxygen sensor (engine/emissions part)

  
  

  The GM Genuine OEM Heated Oxygen Sensor (MPN: 12559850) monitors exhaust oxygen levels to optimize fuel combustion and reduce harmful emissions on select GM vehicles. This authentic General Motors oxygen sensor is engineered to factory specifications and delivers reliable performance for engine management systems. Perfect for drivers seeking genuine replacement parts that meet original equipment manufacturer standards.

  - Heated oxygen sensor designed for precise exhaust gas oxygen detection and emissions control
  - OEM fitment for General Motors vehicles requiring this specific sensor configuration
  - Optimizes air-fuel mixture and engine efficiency while lowering emissions output
  - Compatible with select GM models as a direct replacement part
  - Genuine GM OEM part manufactured to factory standards and backed by General Motors warranty

• Condition: New

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