This engine performance (emission control systems) module is one of a series of competency-based modules in the Missouri Auto Mechanics Curriculum Guide. Topics of this module's five units are: positive crankcase ventilation (PCV) and evaporative emission control systems; exhaust gas recirculation (EGR); air injection and catalytic converters; inlet air temperature and intake manifold heat controls; and spark timing and idle speed controls. Unit 1 includes three lessons: PCV system fundamentals and service; construction and operation of evaporative emission control systems; and servicing evaporative emission control systems. The two lessons in unit 2 cover EGR operation and EGR service. Lessons in unit 3 cover construction/operation of air injection systems and catalytic converters and air injection and catalytic converter diagnosis and repair. Unit 4 contains two lessons, one on heated air inlet systems and the other on intake manifold heat controls. Lessons in unit 5 are on spark timing controls and idle speed controls. Each module of the Auto Mechanic's Curriculum Guide contains seven major components: competency profile; unit and specific objective sheets; information sheets; assignment sheets; job sheets; tests and answers; and a cross-reference table. Each module is packaged in three parts: an instructor's guide, a student reference, and student work sheets. The color-coded instructor's guide contains the lesson materials plus references and notes to the instructor. (NLA)