Technician a says that carbon monoxide (co) and hydrocarbon (hc)
levels should increase if the air injection reactor (air) hoses are pinched off.
technician b says that a defective drive belt may cause air system
problems. who is correct?
a. technician a
b. both technicians a and b
c. technician b
d. neither technician a nor b
15. which of these items will least likely increase pressure in the
evaporative emission control system?
a. returned fuel from the fuel-injection system
b. inlet fuel to the fuel pump
c. fuel temperature
d. volatility of the fuel
12. as the efficiency of the catalytic converter drops through deterioration,
the switching rate of the rear o2 sensor signal will start to look like the front
o2 sensor signal. when the rear o2 sensor signal reaches approximately 75
percent of the front o2 sensor, which of the following is the result?
a. the catalyst beads in the converter should be changed.
b. the diagnostic trouble code is stored with the mil on.
c. the catalytic converter should be replaced.
d. a one-trip flag is set with a code stored, but the mil isn't activated.
7. which of these engine concerns may be caused by a stuck-open
exhaust gas recirculation (egr) valve?
a. ping (spark knock or detonation)
b. engine missing at highway speed
c. excessive nox exhaust emissions
d. rough idle/stalling