Vehicle Emission Standards and Testing; Catalytic Converters
A catalytic converter has to be at least how hot before it begins to work?
500 degrees F 2,000 degrees F 1,500 degrees F 1,000 degrees F
What is applied to the ceramic substrate to make the surface porous?
Aluminum Honeycomb filler Cerium Washcoat
Which exhaust gas reading indicates a good catalytic converter?
CO is zero O2 is zero Both CO is zero and O2 is zero Neither CO is zero nor O2 is zero
An ignition fault could cause excessive exhaust emissions of ________.
CO2 CO HC NOx
What term describes a catalytic converter as it reaches its effective temperature?
Consumption Initiation Light off None of these
All of the gasses are measured in percentages EXCEPT ________.
HC CO CO2 O2
Which gas indicates efficiency? (The higher the level of this gas, the more efficient the engine is operating.)
HC CO CO2 O2
Which gas is generally considered to be the lean indicator? (The higher the level of this gas, the leaner the air-fuel mixture.)
HC CO CO2 O2
Which gas is generally considered to be the rich indicator? (The higher the level of this gas, the richer the air-fuel mixture.)
HC CO CO2 O2
What two primary sensors does the PCM use to check the catalytic converter?
MAP and TP Pre-cat oxygen sensor and MAF Pre-cat and post-cat oxygen sensor Catalytic converter temperature sensor and rear oxygen sensor
This drawing shows a catalytic converter with exhaust gases entering the CAT. What are the gases changed to at the CAT outlet?
NOx HCO and CO H2O and CO2 Both NOx and H2O and CO2
Technician A says that carbon inside the engine can cause excessive NOx to form. Technician B says that excessive NOx could be caused by a cooling system fault causing the engine to operate too hot. Which technician is correct?
Technician A only Technician B only Both technicians Neither technician
Technician A says that high HC emission levels are often caused by a fault in the ignition system. Technician B says that high CO2 emissions are usually caused by a richer-than-normal air-fuel mixture. Which technician is correct?
Technician A only Technician B only Both technicians Neither technician
Technician A says that the catalytic converter is warranted for 8 years or 80,000 miles, whichever comes first. Technician B says that after replacing the catalytic converter, the old converter must be kept for possible inspection for 60 days. Which technician is correct?
Technician A only Technician B only Both technicians Neither technician
Two technicians are discussing the testing of a catalytic converter. Technician A says that a vacuum gauge can be used and observed to see if the vacuum drops with the engine at 2500 RPM for 30 seconds. Technician B says that a pressure gauge can be used to check for backpressure. Which technician is correct?
Technician A only Technician B only Both technicians Neither technician
A catalytic converter is being tested with an infrared pyrometer. Which is an acceptable (good converter) result?
The temperature of a catalytic converter is the best test to perform to locate a restricted unit Both the inlet and outlet should be the same temperature after the converter reaches operating temperature The inlet should be hotter than the outlet by 10% The outlet should be hotter than the inlet by 10%
In areas with emission testing, a MIL that is "ON" causes the vehicle to ________ the emission inspection.
skip bypass fail pass
A catalytic converter can be harmed by ________.
sulfur from poor-quality fuel excessive engine oil antifreeze Any of these
OBD-II equipped vehicles are required to turn on the malfunction indicator lamp if the system has detected an exhaust emission level that is ________ the FTP limit.
the same as 1.5 times or higher than 1.5 times less than None of these
HC and CO are high and CO2 and O2 are low. This could be caused by a ________.
clogged EGR passage rich mixture lean mixture defective ignition component
Oxides of nitrogen results from a combination of nitrogen and ________.
nitrogen hydrogen carbon oxygen
