Spark plug replacement requires a spark plug socket and extension that fit onto a ratchet, with the socket lined with a rubber grommet to protect the porcelain insulator and hold the plug during removal. A wire-type feeler gauge is needed to check and adjust the spark plug gap, along with a torque wrench to tighten the new plugs to the specified torque. Inspect each new plug for defects, avoiding any with cracks in the porcelain insulator. Check the electrode gaps using the wire gauge; if the gap does not slide between the electrodes with slight drag, the spark plug needs replacement. The gap should match the specified measurements, and if it is incorrect, the spark plug must be replaced without attempting to adjust it. If the side electrode is misaligned with the center electrode, replacement is necessary. Avoid using a wire brush or wheel on iridium or platinum-tipped spark plugs. For removal, on 2.0L models, the intake manifold must be taken off, followed by the ignition coils and then the spark plugs using the socket and ratchet. Clear any dirt or debris from the spark plug area with compressed air or a bicycle pump. Compare each old spark plug with a reference chart to assess the engine's running condition. For installation, apply anti-seize compound to the plug threads, ensuring it does not reach the lower threads. To prevent cross-threading, use a snug-fitting rubber hose over the spark plug for alignment. Tighten the plug to the specified torque and repeat the process for the remaining plugs. After all plugs are replaced, reinstall the ignition coils and the intake manifold on 2.0L models.