Vivid racing carries 1 step colder iridiumspark plugs by denso for your Porsche 996 c2/c4 3.4l 98-01. These plugs are designed for cars running more horsepower. As you increase power, the need for a faster colder spark is necessary for proper tuning. These spark plugs are a great upgrade for all cars in all stages. They are sold individually. You need 6 for the 996 engine. Densos iridium power spark plugs help your vehicle achieve unparalleled performance. It alters the belief that a mere spark plug can add power and mileage. This is done by combining an iridium center electrode with a tapered cut u-groove ground electrode. Iridium conducts electricity better than platinum, however what makes it exceptional is ...(choose a part on the right to read more)