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2003 SATURN L-SERIES
2.2L I4•FWD•AUTOMATIC•gas
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Repairs0Labor496Torque3468Fluid7DTC1803Battery1Maintenance0Recalls0
P0426moderate severityPowertrain

Catalyst Temperature Sensor Range/Performance (Bank 1, Sensor 1)

on 2003 Saturn L-Series 2.2L I4 · FWD

What this code means

The PCM detected the bank 1 catalyst temperature sensor reading is out of the expected range. This indicates the sensor value is implausible.

Symptoms

  • Check engine light on
  • Failed emissions test
  • Erratic temperature data

Common causes

  • Faulty catalyst temperature sensor
  • Wiring resistance or corrosion
  • Poor connector contact
  • Failed catalytic converter

Diagnostic steps

  1. Scan and confirm P0426
  2. Review sensor live data
  3. Inspect wiring and connector
  4. Test sensor against known values
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