I used the regular NGK PMR8B plugs as recommended by Ferrari and Maserati (these spark plugs has been made on request by Ferrari). They are double platinum. The plug gap is preset at 0.7mm. 8 of PMR8B means the heat range between 2 and 11. So it is rather a ďcoldĒ spark plug as 8 represents the resistance to heating up.
The first picture are the 4 plugs of bank 2 and a new plug. They all have a light grey insulator legs without deposits which means the engine is running with the right operation temperatures. A white insulator would mean a hot running engine (temperature higher then 800C), probably running lean or blocked injectors. A fooled insulator would mean a cold running engine (temperature lower than 450C), probably running rich, excessive idling or lack of air intake
flow (dirty air filters). A broken insulator is getting more serious as it may cause damage to the piston or a foreign object is present in the combustion chamber.
My plugs donít have the usual Corona ring (brown ring on the white insulator base) which is normal as there shouldnít be any electrical stress in the air around the plug because the plugs are entirely isolated inside the coil pack. A brown ring would mean that the coil pack isnít tightened enough or the coil gasket is letting air getting inside.
The second picture are the 4 plugs of bank 1.
A last very important thing : donít start the engine after changing the spark plugs. Switch off the main power switch and leave it off during the night (as a precaution, always leave a door open before switching off the main power and don't close the front luggage compartment...).
The day after, do the entire self-learning procedure : cycle the main power switch, wait 15/20 sec, switch off A/C, fan, lights, radio etc, cycle the ignition in position II, wait 15/20 sec, start the engine and let it idle for min. 15 minutes. You're done
Next job will be how to replace the active carbon filter.