Exam 34: Emission Control Diagnosis and Service

Technician A says a pressure gauge can be inserted into the oxygen sensor bore, and back pressure caused by the catalytic converter can be measured. Technician B says a vacuum gauge can be used to identify a restricted converter. Who is correct?

What is an OBD-II monitor?

Spark knock may be referred to as ____________________.

Before the EVAP system on an OBD-II vehicle can be pressure tested or smoke tested for leaks, a scan tool must be used to _____.

Which of the following is a cause of detonation?

An exhaust ___________________ is one of the valuable diagnostic tools for driveability problems.

Crankcase pressure forcing crankcase gases through the clean air hose and into the air cleaner is being discussed. Technician A says the cause may be an excessive amount of blowby. Technician B says the cause may be a restricted PCV valve. Who is correct?

Technician A says a defective throttle position (TP)sensor will not affect the EGR valve operation. Technician B says a defective engine coolant temperature (ECT)sensor will not affect the EGR valve operation. Who is correct?

Technician A says a defective PCV valve may cause rough idle operation. Technician B says the PCV system depends upon a properly sealed engine to perform correctly. Who is correct?

A catalytic converter may be tested with a ______.

Excessive carbon monoxide (CO)forms when there is not enough O₂ to combine with the carbon during combustion.

Because it does not support combustion and is unlikely to cause an explosion, nearly all OEMs recommend ___________________ rather than compressed air for pressure-testing the EVAP system.