Toyota Repair: 1997 V6 Camry Engine misfires, fuel filter replacement, vacuum leak

Question
Ted,
I have a 1997 V6 Camry with 92,000 miles.  When I start it up the engine seems to surge back and forth, and idle roughly with misfires and the check engine light is on.  I had it scanned and the codes P0300, P0301, P0302, P0303, P0304, P0305, and P0306 were present.  I was told that this represents misfiring of all cylinders.  The mechanic I spoke with said he was not sure of the problem, but that he didn’t think it had anything to do with a vacuum leak.  He suggested a fuel filter replacement to start with.  I read some of your articles where you had mentioned coil packs and was wondering if this had anything to do with it, although it seems unlikely that all three of them would go at the same time.  Also, after I reach 15 mph or so the car feels like it accelerates and cruises smoothly. Thank You,
Garrett Sell


Answer
This does not sound like there is a problem with the coil packs, there is another source that is causing the random misfires in all cylinders,are there any other codes?
The problem could be caused by and EGR problem, contaminated fuel or a vacuum or intake air leak, these are common to all cylinders.
Going back to basics, make sure that the spark plugs are good, these are platinum plugs and should be replaced evey 60,000 miles. The fuel filter should be replaced at this mileage but I don't think it will fix the problem.