Engine Performance - Test 2

Tech A says that high HC emission levels are often caused by a fault in the ignition system. Tech B says that high CO2 emissions are usually caused by a richer-than-normal air-fuel mixture. Which tech is correct?

• Tech A

• Tech B

• Both A & B

• Neither A nor B

An ignition fault could cause excessive _________ exhaust emissions.

• HC

• CO

• NO_x

• CO₂

Which of the following could NOT be the cause of an ignition fault?

• Faulty spark plug

• Faulty ignition wire

• Faulty TP sensor

• Faulty ignition coil

HC and CO are high and CO₂ and O₂ are low. This could be caused by a _____________.

• Rich mixture

• Lean mixture

• Defective ignition component

• Clogged EGR passage

A clogged EGR passage could cause excessive ___________exhaust emissions.

• HC

• NO_x

• CO

• CO₂

A crack in an exhaust manifold could lead to what trouble code being set by the PCM?

• HO2SHeater circuit low code

• Rich fuel trim code

• Exhaust backpressure code

• Lean fuel trim code

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

Tech A says that carbon inside the engine can cause excessive NO_x to form. Tech B says that excessive NO_x could be caused by a cooling system fault causing the engine to operate too hot. Which tech is correct?

• Tech A

• Tech B

• Both A & B

• Neither A nor B

The maximum acceptable level of HC should be:

• 500 ppm or less

• 10% or less

• 50 ppm or less

• Less than 100 ppm

Which gas is generally considered to be the lean indicator ? (the higher the level of this gas, the leaner the air-fuel mixture).

• HC

• O₂

• CO₂

• NO_x