What you will need
- Allow the engine to cool down.
- Open the hood by pulling the hood release under the dashboard.
- Remove two 10mm bolts on top of the engine cover. Remove engine cover by pulling it forward and up.
- Unplug the electrical connector from the ignition coil by pressing the connector first then pulling it off the coil.
- Remove ignition coil 10mm bolts.
- Next, remove the ignition coils simply by lifting them up.
- Remove the spark plugs. You will need a socket extension and a 5/8 socket to remove the plugs. Be gentle. They are prone to breaking off in the cylinder head.
- Once you have the plugs out, inspect them to make sure they are not fouled, covered in oil, or have straps missing. If they do, you have bigger problems than just spark plugs.
- Install the new plugs, put the ignition coils back on, and reconnect them.
- Start the car and make sure the engine is running smoothly and not shaking.
If the check engine light was on, it will take a few days for it to reset it on its own. Or use an OBD-II scanner to reset the check engine light yourself.
Follow this guide to learn how to reset the Mitsubishi check engine light.