I think the NTHSA would have a different opinion on the dealer fixing
the problem at no cost while it was under warranty.  If there is
Technical Service Bulletin called out and your car is under warranty it
is a given that the dealer will correct the problem.  If not go through
the Zone Rep or call Nissan direct and if that fails you go to the
National highway Transportation Safety Agency.  Yes, a TSB is not a
recall.  But, if reported to the government and the dealer refuses to
correct the problem there is going to be an issue...

You're correct, you won't automatically get it fixed for free.  But a
dealer will be hard-pressed to deny service when you have a TSB in
hand that describes the problem you're having.

I've shown them a couple of TSBs that they said they knew nothing
about (most notably the fuel-cut issue) and had to hammer them until I
got action.  As far as I was concerned, my car was under warranty, it
was exhibiting a serious problem, and it was described in their TSB.
There'd be trouble if they didn't do something about it.  If they
still refuse, you can call the territory manager next.  After that,
there are still options.

I have no desire to go through this process again, but in the 80's I
went through the lemon-law process with a car the dealer couldn't fix.
If you decide to back down and take no action you won't get anywhere
and will have to live with the problem.

I agree if you're out of warranty you'll have a tough time getting
action, but in some cases there is still a possibility.  I have heard
of people getting all their coils replaced free after the warranty
expired (a 2000 in particular).  It's now 2004.. depending on the
mileage the original poster has today, he's probably out of luck.  But
if his mileage was low, he could argue that the coils had an inherent
(and known) problem and should not have failed so quickly.

I'm no expert.... but, coils can be had on ebay. I had a problem with
a coil that didn't set a code telling which coil. I had my local
mechanic change a front and back coil and give me the old ones. The
idea was that I would change the next set if this didn't solve the
problem and put the old ones in. The initial replacement solved the
problem.  $0.02 worth....
Bruce

The knock-sensor will need to trip 2 times in a row.  The "Service Engine"
light will then stay on.  

Luckly this happened to my 2000 Nissan while it was still under the 36/3
warranty and I got all six replaced for free.  However I don't expect
these to last...