Hey guys, looking for some help/advice here…

The Background.
-2003 Pathfinder LE, 4x4 (V6 3.5L) almost at 100K
I have a 3rd car, I figured I would just do the maintenance myself. Changed the oil (done that plenty of times), changed the diff fluid-front and back (done that on other vehicles before), then I changed the spark plugs and coils, I’ve done it before on other vehicles. Have a Chilton manual for the pathfinder and followed it to the T.
Disconnected the harness, unscrewed the top housing, pulled the coil with the top housing out, removed dust cover with coil and trashed, installed new dust cover and coil with dielectric grease, removed old spark plug, and installed new plug with a bit of anti-seize, and installed everything in reverse order as installation. I should also add that I did not change or check the gap on the spark plugs as they were platinum coated and the Chilton manual recommended against it for platinum or iridium plated plugs. All plugs were done one at a time.

The Problem.
When I tried to crank the engine, everything sounded good when the starter turned, but the engine would not catch and fire. I tried several times with no success. Then, finally when I gave it some gas while turning the key, it started, but was pretty sketchy. The engine was idling fairly low (~500-600 RPM), and the car was shaking. Rev-ed it a few times and it sounded OK, but the idle was still off. Took it for a spin and didn’t notice any lack of power, however I’m not the normal driver. Turned it off, waited 15 minutes, and tried it again, and the same thing happened, had to give it gas for it to start. Drove it to work the next day, same thing happened, but it acted fine while driving. No check engine light or anything.

Possible Causes?
1. One of the spark plugs wasn’t torqued enough, and therefore the engine cannot get the require compression or vacuum in that cylinder.
2. One of the spark plugs isn’t firing.
3. I somehow screwed up the intake, or another harness while I was in there fiddling around.
4. Needs a tune up?

As for #1, I torqued per the specifications, but I think this is the most likely candidate.
For #2 – I visually checked all the connections and they looked fine.
#3 – I did disconnect the rubber from the engine intake, but since it functions fine while driving I don’t think this is the problem.

The thing that is really baffling me is that if it is caused by #1 or #2, wouldn’t the check engine light come on?

Starting to get the Ol’ “You ruined my car” from my wife, so any help/advice would be greatly appreciated.

C