Free NAPA Engine Performance & Diagnostics Questions and Answers

Question 1

What does a misfiring cylinder usually indicate?

Accepted Answer

Faulty spark or fuel issue

Answer

High oil pressure

Answer

Low coolant levels

Answer

Clogged air filter

Question 2

Which sensor helps monitor the air-fuel mixture?

Accepted Answer

Oxygen sensor

Answer

Throttle position sensor

Answer

Knock sensor

Answer

Crankshaft sensor

Question 3

What is a typical symptom of a failing mass airflow sensor?

Accepted Answer

Poor engine performance

Answer

Excessive exhaust smoke

Answer

High coolant pressure

Answer

Illuminated ABS light

Question 4

Which component regulates ignition timing?

Accepted Answer

Engine control module

Answer

Ignition coil

Answer

Fuel injector

Answer

Radiator fan

Question 5

What tool is commonly used to read engine fault codes?

Accepted Answer

OBD-II scanner

Answer

Tachometer

Answer

Voltmeter

Answer

Multimeter

Question 6

Which of the following could trigger the check engine light?

Accepted Answer

Loose gas cap

Answer

Worn brake pads

Answer

Dirty air filter

Answer

Low windshield washer fluid

Question 7

Why is a compression test important for engine diagnostics?

Accepted Answer

Identifies internal engine wear

Answer

Checks spark plug gap

Answer

Tests oil viscosity

Answer

Evaluates battery voltage

Question 8

Which system ensures the engine operates at ideal temperature?

Accepted Answer

Cooling system

Answer

Ignition system

Answer

Fuel system

Answer

Transmission system

Question 9

Which engine component is directly driven by the crankshaft?

Accepted Answer

Camshaft

Answer

Water pump

Answer

Oil filter

Answer

Radiator