Students frequently use acronyms freely without fully understanding what each letter represents. This guide should help students correlate these acronyms with the purpose, function, or test, and probable malfunction for each of the four. By having students complete this exercise for two different vehicles, comparisons may be drawn. Carefully review student responses since many imported and late model domestic models use widely diverse systems. Wide-open throttle requires maximum flow.
Vacuum approaches zero, thus, the valve fully opens.
EGO's function only in closed loop. Abnormally high O2 levels could result from a malfunctioning air management system or leaking exhaust system. Automechanics, 4th Edition.