Could engine idles rough be caused by worn spark plugs?

Old plugs cause uneven combustion and shake.

Could engine idles rough be caused by vacuum leak?

Cracked hoses or intake gaskets let unmetered air in. Symptoms: high idle, surging idle.

Carbon buildup restricts the throttle plate. Cleanable with throttle body cleaner.

Older cars have an IAC that fails and causes uneven idle.

Bad readings make the engine guess at fuel mixture, causing rough running.

Severity is rated Medium. Get the codes scanned first. If no codes, start with throttle body cleaning and a spark plug check.

A rough idle often points to an air, fuel, or ignition issue.

Severity: Medium

Get the codes scanned first. If no codes, start with throttle body cleaning and a spark plug check.

Worn spark plugs: Old plugs cause uneven combustion and shake. Shop spark plugs
Vacuum leak: Cracked hoses or intake gaskets let unmetered air in. Symptoms: high idle, surging idle. Shop intake manifold gasket
Dirty throttle body: Carbon buildup restricts the throttle plate. Cleanable with throttle body cleaner. Shop throttle body cleaner
Failing idle air control valve: Older cars have an IAC that fails and causes uneven idle. Shop idle air control valve
Bad MAF sensor: Bad readings make the engine guess at fuel mixture, causing rough running. Shop mass airflow sensor