New 03 DII owner with 72K miles. I got a misfire #5 and an O2 error about a week ago. Now I'm getting misfire code on 1,3,5,7, lean fuel and O2 errors. Is this a coil pack issue?

 

That would not be a coil pack I don't think. If it were 1,6,4,7 or 2,3,8,5 then it would be a coil pack.

 

bring us all the codes. what type of wires and plugs do you have?

 

You need a good old fashioned tune up, that means new plugs and wires.
I prefer Iridium plugs but you must use Magnecor plug wires, if you dont you will be doing the job again in a couple of months.
www.apexperformance.net has the best price on them.

 

could it be a head gasket?

 

The codes are: P0103, P0171, P1300, P0305, P1171, P0303, P0300, P0301, P0307

 

wires and plugs appear to OEM, I checked the #5 plug when the problem first started, no fouling, oil or burnt parts

 

No if you had misfires in just 1,2,7, or 8 then you would start thinking head gasket. Start with a tuneup clear the codes and see what comes back.

 

OEM is not good enough any longer. get soem Bosch +4 platinums or what those other guys use Iridiums and some 8mm Magnecor wires. also might wanna try doing an induction cleaning and clean the throttle body. clear the codes drive it and see if anything comes back. i bet not.