Code 21

1987 Chrysler New Yorker 2.2 ESECTION Code 21

Problem with O2 Sensor feedback circuit. Occurs if engine is in closed loop, but O2 sensor stays rich or lean (no signal) for more than 22 seconds. Engine temperature should be above 170°F (77°C) and engine speed is above 2000 RPM.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.