Exhaust After-treatment Systems Ch 48 Service
and Maintenance Exam Revision Questions with
Reliable Solutions
What is the current national maximum sulfur content permitted in a diesel fuel sold for on-highway, and
most off-highway, use in the United States or Canada? - Answer 0.0015% S
When using an opacity meter to perform a J1667 smoke density test, which of the following tests would
require a chassis dynamometer? - Answer rated speed and load
Technician A says that when ambient temperature drops below 35 degrees Fahrenheit, outdoor J1667
opacity testing on truck diesel engines does not produce meaningful data. Technician B says that when
outdoor temperatures exceed 80 degrees, a J1667 test cannot be performed. Who is right - Answer A
When performing the required throttle snaps during a J1667 opacity test, how long should each snap be
held full travel? - Answer until prompted to release but not more than 4 seconds
Technician A says that when performing a J1667 opacity test, the exhaust stack diameter must be
correctly entered into the opacity meter instrument or the results will not be meaningful. Technician B
says that the ambient temperature must exceed 35 degrees Fahrenheit (2 degrees Celsius) before a valid
J1667 opacity test is undertaken. Who is right? - Answer A & B
Which of the following is the recommended method of cleaning a fouled EGR cooler core? - Answer
ultrasonic bath cleaning
What color is the cap on a DEF reservoir? - Answer blue
What is the maximum ambient temperature in which a valid J1667 opacity test can be undertaken? -
Answer 86 degrees Fahrenheit (30 degrees Celsius)
What temperature does DEF freeze at? - Answer 12 degrees Fahrenheit (-11 degrees Celsius)
and Maintenance Exam Revision Questions with
Reliable Solutions
What is the current national maximum sulfur content permitted in a diesel fuel sold for on-highway, and
most off-highway, use in the United States or Canada? - Answer 0.0015% S
When using an opacity meter to perform a J1667 smoke density test, which of the following tests would
require a chassis dynamometer? - Answer rated speed and load
Technician A says that when ambient temperature drops below 35 degrees Fahrenheit, outdoor J1667
opacity testing on truck diesel engines does not produce meaningful data. Technician B says that when
outdoor temperatures exceed 80 degrees, a J1667 test cannot be performed. Who is right - Answer A
When performing the required throttle snaps during a J1667 opacity test, how long should each snap be
held full travel? - Answer until prompted to release but not more than 4 seconds
Technician A says that when performing a J1667 opacity test, the exhaust stack diameter must be
correctly entered into the opacity meter instrument or the results will not be meaningful. Technician B
says that the ambient temperature must exceed 35 degrees Fahrenheit (2 degrees Celsius) before a valid
J1667 opacity test is undertaken. Who is right? - Answer A & B
Which of the following is the recommended method of cleaning a fouled EGR cooler core? - Answer
ultrasonic bath cleaning
What color is the cap on a DEF reservoir? - Answer blue
What is the maximum ambient temperature in which a valid J1667 opacity test can be undertaken? -
Answer 86 degrees Fahrenheit (30 degrees Celsius)
What temperature does DEF freeze at? - Answer 12 degrees Fahrenheit (-11 degrees Celsius)
