Intake Manifold Gasket

I've recently posted about my check engine light/rough idling on my 99 Rodeo (V6 4WD). I've had the spark plugs replaced (a few weeks ago) and now it is doing this again. Someone suggested that it could be the intake manifold gasket. I have a few questions about this:
1. I am the 2nd owner but my wife and I purchased a used car warranty here in Indiana that provides a full warranty (including Powertrain) up until there is 100K on the car.....we only have 60k. Should the failure of the intake manifold gasket be covered under such a warranty (and anything else associated with the check engine light coming on)? I've been reading on these forums and a few people suggest that this is fixable under warranty.
2. If not covered under warranty, how difficult is this to fix?
Thanks!

if it is under 60k and less then 5 yrs since it was purchased, then yes it should be covered. If not the parts cost under 40 bucks and jsut about any mechanic should be able to replace it for 250-300 bucks.

Here is a write up how to with part number:
http://www.geocities.com/endre_rl/isuzufaq.htm#faq5

I think the warranty amigo is talking about is the original isuzu warranty. When I got my 00 rodeo the gaskets were gone and I took it to a shop and then found out that it was covered at the dealership still!! Doesnt hurt to check.