S420 CYLINDER LAYOUT
The cylinder firing order is 1-5-4-8-6-3-7-2. The order of the cylinders is (from the front of the car) 1-2-3-4 on the right, and 5-6-7-8 on the left. I'll try and find an image.
http://autorepair.about.com/library/firing_orders/bl-fo-4094.htm Found a site that gives a diagram.
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