150 · AUTOMOTIVE SENSORS ACKNOWLEDGMENT I wish to acknowledge the technical assistance of my colleague Khizer Tufail in preparing some sections of this review. ABBREVIATIONS AFR BMEP CA CAD CCD CARS CO DISI ECU ECM EGO EOI EMI EGR Air-fuel ratio Brake mean effective pressure Crank angle Crank angle degrees Charge-coupled device Coherent antistokes raman spectroscopy Carbon monoxide Direct-injection spark-ignition Engine control unit Engine control module Exhaust gas oxygen (sensor) End of injection Electromagnetic interference Exhaust gas recirculation