SMOG REPAIR TECHNICIAN EXAM | 161
QUESTIONS | WITH COMPETE
SOLUTIONS!!
1 of 160
Term
What is the normal voltage range for a properly working upstream
oxygen sensor?
Give this one a try later!
0.1V - 0.9V 1.5V - 2.0V
2.0V - 4.0V 0V - 0.3V
, Don't know?
2 of 160
Term
Which of the following is a common symptom of a stuck-closed EGR
valve?
Give this one a try later!
High NOx emissions High Co2 emissions
Worn Spark plugs Clogged EGR passages
Don't know?
3 of 160
Term
Which of the following is an advantage of a leakdown test over a
compression test?
Give this one a try later!
, Subletting is not allowed unless
permitted under specific Rich air-fuel mixture
BAR
guidelines
A leakdown test identifies the
source of cylinder leakage,
Leaking coolant into the engine
while a compression test does
not
Don't know?
4 of 160
Term
If a cylinder has low compression that improves after adding oil,
what is the most likely issue?
Give this one a try later!
Carbon buildup Blown head gasket
Worn piston rings Burned exhaust valve
Don't know?
5 of 160
Term
, A vehicle fails a smog test with the following emissions:
HC: 210 ppm
CO: 2.8%
CO₂: 11.0%
O₂: 0.4%
NOx: 150 ppm
What is the most likely cause of this failure?
Give this one a try later!
Clogged catalytic converter Vacuum leak
Bad oxygen sensor EGR valve stuck closed
Don't know?
6 of 160
Term
A vehicle's OBD-II connector shows no scan tool communication.
Upon inspection, you find no voltage at Pin 16. What is the most
likely cause?
Give this one a try later!
A faulty ground wire A bad oxygen sensor
QUESTIONS | WITH COMPETE
SOLUTIONS!!
1 of 160
Term
What is the normal voltage range for a properly working upstream
oxygen sensor?
Give this one a try later!
0.1V - 0.9V 1.5V - 2.0V
2.0V - 4.0V 0V - 0.3V
, Don't know?
2 of 160
Term
Which of the following is a common symptom of a stuck-closed EGR
valve?
Give this one a try later!
High NOx emissions High Co2 emissions
Worn Spark plugs Clogged EGR passages
Don't know?
3 of 160
Term
Which of the following is an advantage of a leakdown test over a
compression test?
Give this one a try later!
, Subletting is not allowed unless
permitted under specific Rich air-fuel mixture
BAR
guidelines
A leakdown test identifies the
source of cylinder leakage,
Leaking coolant into the engine
while a compression test does
not
Don't know?
4 of 160
Term
If a cylinder has low compression that improves after adding oil,
what is the most likely issue?
Give this one a try later!
Carbon buildup Blown head gasket
Worn piston rings Burned exhaust valve
Don't know?
5 of 160
Term
, A vehicle fails a smog test with the following emissions:
HC: 210 ppm
CO: 2.8%
CO₂: 11.0%
O₂: 0.4%
NOx: 150 ppm
What is the most likely cause of this failure?
Give this one a try later!
Clogged catalytic converter Vacuum leak
Bad oxygen sensor EGR valve stuck closed
Don't know?
6 of 160
Term
A vehicle's OBD-II connector shows no scan tool communication.
Upon inspection, you find no voltage at Pin 16. What is the most
likely cause?
Give this one a try later!
A faulty ground wire A bad oxygen sensor
