SOS MECHANIC CERTIFICATE -ENGINE
TUNE-UP/PERFORMANCE EXAM |
COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS | LATEST UPDATE
(2026) | ALREADY GRADED A+
The engine vacuum is low but steady - CORRECT ANSWER -Retarded Timing
The Purpose of catalytic converter - CORRECT ANSWER -oxidize hc co into c02 and h20
What vehicles are designed to go into a closed loop operation when - CORRECT ANSWER -all of
the above
Diagram shows a vacuum hose connected to "p vacuum" this means the hose should be
connected - CORRECT ANSWER -above the throttle plate
If the voltage spike is not high enough on one cylinder, what is the most likely source of the
problem. - CORRECT ANSWER -a failed spark plug
wide-open-throttle the power train control module reverts - CORRECT ANSWER -open loop, rich
mixtures
during a cylinder leakage test air escaping through the throttle body means there is a leak at -
CORRECT ANSWER -the intake valve
higher than normal oxides of nitrogen (n0x) emissions may be caused by - CORRECT ANSWER -
all of the above
, A reading of 8 volts on meter 2 while cranking would indicate - CORRECT ANSWER -an excessive
ground circuit voltage drop
emission control systems are installed on engines to reduce what 3 specific exhaust products -
CORRECT ANSWER -Hydrocarbons, carbon monoxide and oxides of nitrogen
You have verified a slow cranking complaint, which of the following should you do next -
CORRECT ANSWER -Determine the condition of the battery
The Egr System is designed to - CORRECT ANSWER -cruise
You are monitoring the tps signed voltage digital volt ohm - CORRECT ANSWER -A smooth
voltage increase to about 4.5 v
an electronic fuel injected system that sprays into the throat of intake - CORRECT ANSWER -a
throttle body injections system
What is the function of the egr valve - CORRECT ANSWER -it recalculates exhaust gasses into the
intake
A customer brings vehicle to you with a concern of low power - CORRECT ANSWER -all of the
above
A reading of 1v on meter number 1 cranking - CORRECT ANSWER -Do acceptable voltage drop
You are checking the 02 during closed loop 450 to 500 - CORRECT ANSWER -the sensor is
sluggish and probably bad
TUNE-UP/PERFORMANCE EXAM |
COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS | LATEST UPDATE
(2026) | ALREADY GRADED A+
The engine vacuum is low but steady - CORRECT ANSWER -Retarded Timing
The Purpose of catalytic converter - CORRECT ANSWER -oxidize hc co into c02 and h20
What vehicles are designed to go into a closed loop operation when - CORRECT ANSWER -all of
the above
Diagram shows a vacuum hose connected to "p vacuum" this means the hose should be
connected - CORRECT ANSWER -above the throttle plate
If the voltage spike is not high enough on one cylinder, what is the most likely source of the
problem. - CORRECT ANSWER -a failed spark plug
wide-open-throttle the power train control module reverts - CORRECT ANSWER -open loop, rich
mixtures
during a cylinder leakage test air escaping through the throttle body means there is a leak at -
CORRECT ANSWER -the intake valve
higher than normal oxides of nitrogen (n0x) emissions may be caused by - CORRECT ANSWER -
all of the above
, A reading of 8 volts on meter 2 while cranking would indicate - CORRECT ANSWER -an excessive
ground circuit voltage drop
emission control systems are installed on engines to reduce what 3 specific exhaust products -
CORRECT ANSWER -Hydrocarbons, carbon monoxide and oxides of nitrogen
You have verified a slow cranking complaint, which of the following should you do next -
CORRECT ANSWER -Determine the condition of the battery
The Egr System is designed to - CORRECT ANSWER -cruise
You are monitoring the tps signed voltage digital volt ohm - CORRECT ANSWER -A smooth
voltage increase to about 4.5 v
an electronic fuel injected system that sprays into the throat of intake - CORRECT ANSWER -a
throttle body injections system
What is the function of the egr valve - CORRECT ANSWER -it recalculates exhaust gasses into the
intake
A customer brings vehicle to you with a concern of low power - CORRECT ANSWER -all of the
above
A reading of 1v on meter number 1 cranking - CORRECT ANSWER -Do acceptable voltage drop
You are checking the 02 during closed loop 450 to 500 - CORRECT ANSWER -the sensor is
sluggish and probably bad
