M12 Chapter 8 Quiz
Technician A says some catalytic converters have an air hose connected from the belt-driven air pump to the oxidation catalyst. Technician B says that in these catalytic converters the air hose from the air pump is connected to the reduction catalyst. Who is correct? Group of answer choices A only B only both A and B neither A nor B
A only
Technician A says that the EGR system controls and monitors fuel vapor loss. Technician B says that the EVAP system controls and monitors fuel vapor loss. Who is correct? Group of answer choices A only B only both A and B neither A nor B
B only
An EGR valve that remains open with the engine idling is unlikely to affect engine performance. Group of answer choices True False
False
If the catalytic converter is working properly, the outlet temperature should be lower than the inlet temperature. Group of answer choices True False
False
A PCV valve stuck in the open position may cause a lean air/fuel ratio. Group of answer choices True False
True
A defective EGR system could result in an engine performance complaint. Group of answer choices True False
True
A defective EGR system will cause NOX emissions to be higher than normal. Group of answer choices True False
True
An aftermarket air intake system could affect emission levels. Group of answer choices True False
True
Before performing an emission system diagnosis, the emission control system should be inspected for modification, tampering, and/or missing parts. Group of answer choices True False
True
Critical sensors that monitor catalyst efficiency are located both upstream and downstream of the catalyst. Group of answer choices True False
True
Current evaporative emission (EVAP) systems are fully closed to maintain stable fuel tank pressure and virtually eliminate leakage of fuel vapors into the atmosphere. Group of answer choices True False
True
Gasoline vapors are extremely explosive. Group of answer choices True False
True
Which of the following is the best definition for the catalytic converter? Group of answer choices a device that produces maximum combustion inside the engine a way of cleaning up the exhaust gases after they leave the engine a device that creates extra oxygen to overcome exhaust gases a method of emission control that is now being discontinued
a way of cleaning up the exhaust gases after they leave the engine
The benefits of emission control systems are to: Group of answer choices control hydrocarbon fuel vapors from escaping into the atmosphere convert harmful exhaust gases into less harmful emissions before they leave the tailpipe reduce fuel consumption all of the above
all of the above
The benefits of emission controls are to: Group of answer choices reduce pollutants in the exhaust stream control vapor loss into the atmosphere reduce fuel consumption all of the above
all of the above
The evaporative emissions system reduces the emissions of HC vapors into the atmosphere when the vehicle: Group of answer choices is operating at highway speeds is stationary and the engine is idling is parked with the engine off all of the above
all of the above
All of the following statements about the EGR valve are true, EXCEPT: Group of answer choices the EGR valve creates a controlled vacuum leak between the intake and exhaust manifolds an EGR valve that is stuck closed will cause high NOX emissions the vacuum to many vacuum actuated EGR valves is controlled by a solenoid an EGR valve that is stuck in the open position will cause detonation
an EGR valve that is stuck in the open position will cause detonation
Technician A says that in an OBD II vehicle the EVAP system sends fuel tank vapors to a charcoal canister for storage. Technician B says that in an OBD II vehicle, when proper conditions are present, fuel vapors are purged from the charcoal canister into the intake manifold. Who is correct? Group of answer choices A only B only both A and B neither A nor B
both A and B
The EGR system is designed to reduce which exhaust emission pollutant? Group of answer choices unburned hydrocarbon carbon monoxide carbon dioxide oxides of nitrogen
oxides of nitrogen
If the fuel filler cap leaks, what monitor is designed to detect the leak? Group of answer choices the catalyst efficiency monitor the misfire monitor the EVAP system monitor none of the above
the EVAP system monitor
