Well I can tell you right off the bat that the plugs you installed are basically the worst ones available for these engines, and are known to cause misfires. You may have other issues, but the Bosch Platinum +4 plugs have a documented history of being terrible. The plugs to get are the NGK BKR6EK - just the standard copper version. They're cheap and work very well.
Originally Posted by foaxaca
Here's the latest... Changed our spark plugs, replaced with Bosch Platinum +4 plugs...
1998 BMW 328is
1966 Pontiac GTO
2007 Subaru Impreza 2.5i 5-door
View my photos: Caught in the Wild
Last edited by ZeGerman; 11-11-2012 at 08:57 PM.