Owners of other Mazda vehicles such as the Mazda 2, Mazda 3, Mazda 5, Mazda 6, CX-7, CX-9, and the MX-5 Miata may also find these DIY instructions to be helpful.

The tools needed to complete this procedure include an 8mm socket with a 1/4" drive ratchet, either a 14mm spark plug socket or a 9/16" spark plug socket, a 6" extension bar, a 3/8" drive ratchet and a tube of dielectric grease.

The OEM iridium tipped spark plugs in this 2013 CX-5 were NGK part number ILKAR7L11 (also known as # 94124).

A few other compatible spark plugs with their part numbers are as follows: Denso (4711) IXEH20TT, Champion 9412, Bosch Platinum (6727) HR8NPP302X and Autolite XP5682.

Gently pull the cover straight off the top of the engine.

Set the engine cover aside in a safe place.

If you have access to compressed air or a wet/dry shop vacuum, thoroughly clean off the top of the engine to help prevent from having debris fall down on to the cylinder head when you remove the spark plugs.

Press the release tab on the black plastic electrical connector before sliding the plug straight off the ignition coil.

Remove the ignition coil bolt and set it aside in a safe place.

Lift the ignition coil straight out of the spark plug well and set it aside in a safe place.

Attach the 14mm spark plug socket to a 6" or longer extension bar and the 3/8" drive ratcheting wrench.

(I only had a 9/16" spark plug socket at the time of creating this guide, so that's what I used. A 9/16" socket is just slightly larger than 14mm at about 14.2875mm.)

Then carefully loosen the old spark plug by rotating the wrench in the counterclockwise direction.

Try to avoid using excessive force to loosen the old spark plug to prevent from cracking the ceramic portion of the plug.

If you have trouble loosening the old spark plug, spray a small amount of penetrating oil such as PB Blaster, Liquid Wrench or Kano Kroil and wait at least 15-30 minutes before attempting to loosen it again. If you don't have any penetrating oil, try spraying some WD-40 or warm up the engine for a few minutes to help expand the metal engine block.

Once the spark plug has been loosened, detach the ratcheting wrench from the extension bar and spin it out the rest of the way by hand.

Carefully lift the extension bar and the old spark plug out of the well.

If the rubber insert from the spark plug socket is attached to the old plug, pull it off and push it back in to the socket.

If the electrode end of the old spark plug looks ashy white, the plugs may have been exposed to high temperatures such as overheating or they may be the incorrect heat range for your driving conditions or environment.

On the other hand, if the old spark plug is grey or covered in dark black soot, the engine may be burning oil and should be examined by a professional mechanic.

I recommend buying the OEM parts which are the NGK (94124) ILKAR7L11 iridium spark plugs.

(An optional step is to apply some anti-seize grease to the threads on the spark plug. Most spark plug manufacturers recommend that you should not use anti-seize grease since it can lead to over tightening. Some mechanics believe that using anti-seize grease on the spark plugs will help prevent them from becoming stuck or "frozen" in to the cylinder head if they are not removed again for 100,000 miles.)

If you have a spark plug gap gauge, check that the new spark plugs are gapped to the manufacturer's specification listed on the box. They should be pre-set from the factory, so don't worry if you don't have a gap gauge.

Push the new spark plug in to the 14mm spark plug socket.

Your socket should have a rubber insert or a strong magnet to ensure that the new spark plug remains in place.

Carefully lower the spark plug down in to the well and spin it in by hand in the clockwise direction until it makes contact with the cylinder head.

If you are re-installing the old spark plug, tighten it to just a fraction of a turn past hand tight.

If you are installing a brand new spark plug, tighten it to just past the point when you feel the new crush washer collapse. This should be about

Do not over tighten the spark plug to prevent from cracking the ceramic body or stripping the aluminum threads.

If you have a torque wrench, the specification for tightening the spark plugs in the service and repair manual for the Mazda CX-5 with the Skyactiv G 2.0 I4 engine is 12 to 14 lb-ft or 15 to 20 N-m.

Double check that the new spark plug is tight before moving on to the next steps.

The dielectric grease will help keep out any moisture and prevent corrosion (rust).

Lower the ignition coil down in to the spark plug well.

Re-insert the 8mm bolt and tighten it in the clockwise direction until it is snug.

Try to avoid over tightening the ignition coil bolt to prevent from cracking the plastic housing.

Line up the rubber friction fasteners on the underside of the cover with the metal pegs on the top of the engine.

Gently push the engine cover back in to place.

Start the engine and listen closely for any strange sounds that may indicate a problem such as a disconnected power plug or a loose spark plug.

For more, check out all of my Mazda CX-5 DIY Repair & Maintenance Guides.