I had the engine sputter problem all the time.
Sputter at idle and then engine jerking 4th and 5th gear......at some times - usually when accelerating.
I did the following, first time and myself, took me about 6 hours:
Removed intake manifold and replaced the following:
-installed new valve cover gaskets (didnt replace inner gaskets, but used silicone gasket sealant a bit)
-installed new spark plugs (used NGK iridium. Denso Iridium is also a good choice
)
-installed new intake manifold gaskets
-installed 4 new ignition coils (need 6, but driver side coils can be easily changed later)
I did some tests and it turned out that one or two ignition coils was the problem. I strongly suggest changing 3 ignition coils on passenger side (to access these coils/spark plugs you need to remove intake manifold) and then you can play around with driver side ignition coils.
I would also suggest changing spark plugs as they are not that expensive nowadays - use Denso or NGK Iridium
Hint: 3.0L has the problem when oil goes into the coil shafts - bad inner valve gaskets (you need 2 for V6) so it's always good to replace these gaskets as well (if you see any oil signs in coil shafts).
Hint: Make sure you do not damage the Hose Upper Rad plastic pipe that feeds back the coolant reservoir. It tends to brake quite easily.
And there you go. No more engine sputter. I get more miles per gallon and I am damn happy!
If you have any questions or comments, please post here.
Kev
