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 plugs 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 caps to avoid breaking the wires.
Use a spark plug gapping gauge to achieve the specified gap on your new plugs.
If you have an aluminum engine, you should use an anti-seize lubricant on the spark plug threads to prevent a negative reaction between the two different metals.