Old or faulty spark plugs can affect engine performance. During a tune-up, mechanics often replace spark plugs to ensure proper ignition.

The air filter prevents dirt and debris from entering the engine. A clogged air filter can reduce fuel efficiency and engine performance.

The fuel filter helps keep impurities out of the fuel system. Replacing it during a tune-up can prevent fuel flow issues.

This valve helps regulate and redirect gases from the engine's crankcase. A malfunctioning PCV valve can affect engine performance.

Ensuring that the ignition timing is set correctly is crucial for optimal engine performance and fuel efficiency.

This involves checking the condition of drive belts and hoses, such as the serpentine belt, timing belt, and coolant hoses. Worn-out or damaged belts and hoses can lead to engine problems.

Inspecting the battery, cleaning terminals, and ensuring a secure connection are common steps in a tune-up.

 Checking for leaks, damaged components, or a malfunctioning catalytic converter is part of ensuring the proper functioning of the exhaust system.

 This includes checking and topping up engine oil, transmission fluid, brake fluid, power steering fluid, and coolant.