ASE Exhaust Systems Specialist 2

Question 1

A vehicle has a loud rumbling exhaust noise that increases under acceleration. Which component is the MOST likely cause?

Accepted Answer

A failed muffler with internal baffle damage

Answer

A clogged cabin air filter

Answer

A worn serpentine belt

Answer

A low coolant level

Question 2

What is the primary purpose of the oxygen sensor located upstream of the catalytic converter?

Accepted Answer

To provide air-fuel ratio feedback to the ECM

Answer

To measure exhaust gas temperature

Answer

To monitor converter efficiency only

Answer

To control exhaust valve timing

Question 3

A technician finds soot deposits and a leak at an exhaust manifold flange. What should be done FIRST before replacing the gasket?

Accepted Answer

Inspect the flange surfaces for warpage and cracks

Answer

Replace the entire manifold

Answer

Add exhaust sealant over the leak

Answer

Retorque the lug nuts

Question 4

Which exhaust component converts harmful gases like CO and HC into less harmful substances?

Accepted Answer

Catalytic converter

Answer

Resonator

Answer

Muffler

Answer

Exhaust manifold

Question 5

A rattling noise from under the vehicle is traced to a heat shield. What is the correct repair?

Accepted Answer

Secure or replace the loose heat shield

Answer

Remove the heat shield permanently

Answer

Replace the catalytic converter

Answer

Ignore it as cosmetic

Question 6

Excessive backpressure in an exhaust system is MOST commonly caused by which condition?

Accepted Answer

A restricted or melted catalytic converter substrate

Answer

A cracked tailpipe

Answer

A loose clamp

Answer

A missing tip

Question 7

What tool is used to measure exhaust backpressure on a running engine?

Accepted Answer

A pressure gauge installed at the O2 sensor or test port

Answer

A vacuum gauge only

Answer

A multimeter

Answer

A timing light