Fouled, damaged, or worn out spark plugs can lead to a variety of engine problems, such as misfires, hard starts, increased emissions, and poor fuel economy. For most vehicles, you should replace your spark plugs every 30,000 miles (consult your owner's manual for your specific interval). It is also recommended that you replace your spark plug wires at the same time, or you may still experience misfires or other problems. Follow these 11 steps to give your vehicle a simple ignition tune-up.
Remove each spark plug wire by pulling the boots to avoid breaking the wires.
Use a spark plug gapping gauge to achieve the specified gap on your new plugs.
If your engine has aluminum cylinder head(s), you should use an anti-seize lubricant on the spark plug threads to prevent a negative reaction between the two different metals.