SOS Mechanic Certificate -Engine Tune-
Up/Verified Questions 2025/2026 Study
Guide.With Actual Solutions!!!
The engine vacuum is low but steady - answers Retarded Timing
The Purpose of catalytic converter - answers oxidize hc co into c02 and h20
What vehicles are designed to go into a closed loop operation when - answers all of the
above
Diagram shows a vacuum hose connected to "p vacuum" this means the hose should
be connected - answers above the throttle plate
If the voltage spike is not high enough on one cylinder, what is the most likely source of
the problem. - answers a failed spark plug
wide-open-throttle the power train control module reverts - answers open loop, rich
mixtures
during a cylinder leakage test air escaping through the throttle body means there is a
leak at - answers the intake valve
higher than normal oxides of nitrogen (n0x) emissions may be caused by - answers all
of the above
A reading of 8 volts on meter 2 while cranking would indicate - answers an excessive
ground circuit voltage drop
emission control systems are installed on engines to reduce what 3 specific exhaust
products - answers Hydrocarbons, carbon monoxide and oxides of nitrogen
You have verified a slow cranking complaint, which of the following should you do next -
answers Determine the condition of the battery
The Egr System is designed to - answers cruise
You are monitoring the tps signed voltage digital volt ohm - answers A smooth voltage
increase to about 4.5 v
an electronic fuel injected system that sprays into the throat of intake - answers a
throttle body injections system
, What is the function of the egr valve - answers it recalculates exhaust gasses into the
intake
A customer brings vehicle to you with a concern of low power - answers all of the above
A reading of 1v on meter number 1 cranking - answers Do acceptable voltage drop
You are checking the 02 during closed loop 450 to 500 - answers the sensor is sluggish
and probably bad
A car with dis will not start - answers A defective or misalignment crank sensor
How is fuel pressure controlled in a electric efl - answers Engine vacuum
A vehicle with OBD 2 is being check for poor performance and low power with check
engine light flashing - answers detecting a misfire condition
A weak ignition coil would most likely - answers B
A car will not start because of spark - answers Check for primary circuit at coil
You suspect that the timing chain or belt is jumped or broken - answers all of the above
If the ignition timing will not advance past base timing - answers vehicle in limp mode
When spark Knock occurs - answers The knock sensor signals microcomputer retard
When the microcomputer monitor air flow - answers the proper amount of fuel can be
supplied
The power train control module used the TPS - answers fuel pressure
A high gas level or heavy float in carberated - answers Rich mixture
What increases the production of oxipes - answers high combustion temp
On a OBD 2 system a loose gas cap - answers The malfunction indicator lamp turns on
You have examined a set of spark plugs and found white - answers The plug heat range
is too hot
With the vehicle operating temp and running at 2000rpm - answers oxygen sensor
running rich
Up/Verified Questions 2025/2026 Study
Guide.With Actual Solutions!!!
The engine vacuum is low but steady - answers Retarded Timing
The Purpose of catalytic converter - answers oxidize hc co into c02 and h20
What vehicles are designed to go into a closed loop operation when - answers all of the
above
Diagram shows a vacuum hose connected to "p vacuum" this means the hose should
be connected - answers above the throttle plate
If the voltage spike is not high enough on one cylinder, what is the most likely source of
the problem. - answers a failed spark plug
wide-open-throttle the power train control module reverts - answers open loop, rich
mixtures
during a cylinder leakage test air escaping through the throttle body means there is a
leak at - answers the intake valve
higher than normal oxides of nitrogen (n0x) emissions may be caused by - answers all
of the above
A reading of 8 volts on meter 2 while cranking would indicate - answers an excessive
ground circuit voltage drop
emission control systems are installed on engines to reduce what 3 specific exhaust
products - answers Hydrocarbons, carbon monoxide and oxides of nitrogen
You have verified a slow cranking complaint, which of the following should you do next -
answers Determine the condition of the battery
The Egr System is designed to - answers cruise
You are monitoring the tps signed voltage digital volt ohm - answers A smooth voltage
increase to about 4.5 v
an electronic fuel injected system that sprays into the throat of intake - answers a
throttle body injections system
, What is the function of the egr valve - answers it recalculates exhaust gasses into the
intake
A customer brings vehicle to you with a concern of low power - answers all of the above
A reading of 1v on meter number 1 cranking - answers Do acceptable voltage drop
You are checking the 02 during closed loop 450 to 500 - answers the sensor is sluggish
and probably bad
A car with dis will not start - answers A defective or misalignment crank sensor
How is fuel pressure controlled in a electric efl - answers Engine vacuum
A vehicle with OBD 2 is being check for poor performance and low power with check
engine light flashing - answers detecting a misfire condition
A weak ignition coil would most likely - answers B
A car will not start because of spark - answers Check for primary circuit at coil
You suspect that the timing chain or belt is jumped or broken - answers all of the above
If the ignition timing will not advance past base timing - answers vehicle in limp mode
When spark Knock occurs - answers The knock sensor signals microcomputer retard
When the microcomputer monitor air flow - answers the proper amount of fuel can be
supplied
The power train control module used the TPS - answers fuel pressure
A high gas level or heavy float in carberated - answers Rich mixture
What increases the production of oxipes - answers high combustion temp
On a OBD 2 system a loose gas cap - answers The malfunction indicator lamp turns on
You have examined a set of spark plugs and found white - answers The plug heat range
is too hot
With the vehicle operating temp and running at 2000rpm - answers oxygen sensor
running rich
