I changed 5 of 6 spark plugs on my '03 S today. That's right, only 5. I could not get at the top coil pack mounting bolt of cylinder #4 (left side front). I tried every tool I have to get in there and loosen the bolt but nothing worked.
#1 was difficult but doable and the other 4 were no issue at all.
The car is running great with 5 new and 1 old plug. The 5 I removed looked fine for plugs with ~60,000 miles on them as I assume they are the originals.
Not that I can do anything about it but are there likely to be any issues with having one odd plug out of 6? The ones removed are 4 electrode Beru and the replacements are NGK Iridium.
When I do have to change it I will likely get my indie to do it when I have some other work done that I can't do myself unless someone out there has a suggestion on how to get at the damn bolt.