Automotive Emissions
Catalytic converters are a burn hazard to technicians, since they can reach an operating temperature as high as _____ degrees Fahrenheit.
1,400
To comply with the Clean Air Act of 1977, "self-adjusting" engines were introduced in _____.
1981
Technician A says that a passive sensor can be tested by applying a reference voltage and measuring the voltage drop across the sensor. Technician B says that a passive sensor can be tested by using an ohmmeter to measure its internal resistance. Who is right?
Both A and B
(T/F) Accidents seldom result from breaking safety rules.
False
(T/F) An Allen wrench has an octagonal (eight-sided) shaft.
False
(T/F) Carbon dioxide is toxic exhaust gas.
False
(T/F) For safety, battery charger leads must be connected to the battery after the charger is turned on.
False
(T/F) Oxides of nitrogen can be measured by a three-gas analyzer.
False
(T/F) Semiconductor devices are not damage by static electricity.
False
(T/F) Shop air pressure is seldom higher than 50 psi.
False
(T/F) Tetraethyl lead us still widely used as an anti-knock additive in gasoline.
False
(T/F) The only types of accidents likely to happen in an auto repair shop are fire, electrical shock, and physical injuries.
False
(T/F) The safety catch on a hydraulic lift must be engaged after you work under the vehicle.
False
(T/F) Torx screws have a square indention in their heads.
False
(T/F) if you use power tools carefully, wearing eye protection usually is not necessary.
False
What gases are measured by a two-gas exhaust analyzer?
Hydrocarbons and carbon monoxide
What is used to support a vehicle after it has been raised?
Jack stands
Technician A says that a good catalytic converter should have a 10 degree Fahrenheit temperature difference front to rear. Technician B says catalytic converter temperature readings should be uniform front to back. Who is right?
Neither A nor B
What problems can be caused by an EGR valve that is stuck open?
Rough idle
What is not one of the safety rules that apply when working with gasoline?
Soak up any spills with an oil absorbent
An OBD II drive cycle is being performed on a vehicle, but has to be interrupted. Technician A says that the cycle can be started again immediately. Technician B says that the cycle cannot be started agian until engine coolant temperature drops low enough for the ECM to start in the open loop mode. Who is right?
Technician B
Technician A says that oxides of nitrogen can be measured with a four-gas exhaust analyzer. Technician B says that oxides of nitrogen can be measured only by using a five-gas analyzer. Who is right?
Technician B
The malfunction indicator light in an OBD II system is flashing. Technician A says that this simply indicates a soft problem. Technician B says that means the problem could be damaging the catalytic converter. Who is right?
Technician B
(T/F) A PCV valve should be replaced if it does not rattle when shaken.
True
(T/F) A clogged catalytic converter can increase exhaust system back pressure.
True
(T/F) A soldering iron or gun is heated by electricity.
True
(T/F) A wire wheel in a bench grinder should not be used to clean soft metal or brass parts.
True
(T/F) Air-powered tools should always be lubricated before use.
True
(T/F) Always pull vehicles through shop doors slowly and carefully to make sure they will clear the bottom of the raised door.
True
(T/F) An air injection system problem can cause the engine to backfire.
True
(T/F) Asphyxiation is caused by breathing toxic substances in the air.
True
(T/F) Disconnecting computer wiring with the ignition key on can cause damage to the computer.
True
(T/F) Exhaust leaks will often show up as gray or white carbon lines coming from openings.
True
(T/F) Heat shields must always be replaced after exhaust system repairs.
True
(T/F) Higher-then-normal hydrocarbon readings can be caused by improper ignition timing.
True
(T/F) It is unsafe to work under a vehicle supported only by a jack.
True
(T/F) Key-on/engine-off diagnostics allow the technician to check for trouble codes.
True
(T/F) Power tools must always be used with any safety guards in place.
True
(T/F) Rough engine idle can result from an inoperative PCV system.
True
(T/F) The air hammer tool head must be pressed tightly against the workpiece before the tool is turned on.
True
(T/F) The presence of excessive hydrocarbons in the exhaust is signaled by a "rotten egg" smell.
True
(T/F) Vacuum leaks can affect the operation of a vehicle's computer system.
True
(T/F) Water and acids in the engine exhaust can cause exhaust system parts to fail in a fairly short time.
True
(T/F) You should always have your instructor demonstrate potentially dangerous equipment before you try to use it.
True
The term stoichiometric indicates that a fuel mixture is _____.
chemically correct
A cutting torch generates tremendous heat by burning _____ and acetylene gas.
oxygen
Preignition will cause _____ in the engine.
pinging
The catalytic converter is deigned to _____.
remove pollutants from the engine's exhaust
Typically, if the levels of CO exceed the O2 levels, the air-fuel mixture is _____.
rich
A high carbon monoxide reading from an exhaust analyzer indicated that _____.
the air injection is malfunctioning, idle speed is too low, or ignition timing is too far advanced (All of the above)
