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pre-cat 02 heater sensor

  1. E39 M5 and E52 Z8 Discussion
    Hey Guys, I popped a Code and it came up as: Code 25: Pre-Cat 02 Sensor Heater Control Cyl #1-4 I searched through the Peak code knowledgebase and the DIY and it lead me to check the wiring in the DME and at the link between the sensor and the plug/connection. The connections look fine to me...