What is the first step in checking the condition of a spark plug?

The first step in checking the condition of a spark plug is to remove it from the engine. This is essential because it allows you to have direct access to the spark plug to perform a thorough inspection. Once the spark plug is removed, you can assess its physical condition, look for signs of wear, deposits, and damage, and then proceed to further evaluations such as inspecting the spark plug gap or measuring resistance. Without removing the spark plug, it is impossible to accurately gauge its condition or performance in the engine.

The other tasks, such as inspecting the spark plug gap, checking for engine oil presence, or measuring spark plug resistance, can only be performed once the spark plug has been safely removed from the engine. Starting the evaluation process with removal enables a complete and accurate assessment of the spark plug's condition.