How many spark plugs should be replaced at one time?

[GeorgeFitz]

There is one spark plug per cylinder, so a 3-cylinder car requires 3 spark plugs to be replaced at once, a 4-cylinder car requires 4, and a 6-cylinder car requires 6. Since the discharge gap and resistance values differ between old and new spark plugs, failing to replace all of them may lead to issues such as engine shaking, difficulty in acceleration, and increased fuel consumption. Steps for replacing spark plugs: Open the hood and lift the plastic cover of the engine. Remove the high-voltage distributor wires, marking each cylinder's position to avoid confusion. Use a spark plug socket to remove the spark plugs one by one. While removing, check for any external debris like leaves or dust and ensure they are thoroughly cleaned. Place the new spark plugs into the spark plug holes, hand-tighten them a few turns before using the socket to tighten further. Reinstall the removed high-voltage distributor wires according to the firing order, then secure the cover.