The Car: 2000 Civic Si with stock B16A2.
109K Miles. Bone Stock.
Religious Maintenance when it comes to oil changes, valve adjustments etc.
Oil consumption: It is using almost a quart in 3K miles.

The Situation.
Last time I put new plugs in (NGK OE spec), about 6,000miles ago. I noticed I could not get No.1 Cylinder to torque down to a level I felt satisfied with. ( I use a craftsman 3/8, and I grab it close to head and twist about as hard as my wrist can take without pain, and I'm not that strong of a dude) Now I have always used a bit of antiseize, although I do read this is not exactly required these days. Like I said the one cyl is not quite snug, but it doesn't seem to be backing off with time or mileage, So I just left it at that.

The Symptom: (which I dont recall being there before I changed these plugs).
Car's idle is dropping after a rev. Example: backing up, giving it some gas, as soon as I put the clutch in and brake, the revs drop to about 200 and it stays on (barely) then returns to normal idle a few seconds later. Same thing happens when launching to inch up in traffic. Starting after the proper priming has been hit or miss. Sometimes normal sometimes it chokes and requires a second turn.

Videos:
Idle issue after rev.:http://www.youtube.com/watch?v=nAAidn2HSmc

Pulls well otherwise:http://www.youtube.com/watch?v=D5OikpCTdZg

Fuel economy doesn't seem to be affected, and from what I can tell I haven't lost any power. I don't notice any acting up upon hard load.

I'm wondering if it makes sense that there would be a connection between this spark plug problem and my symptoms. I am quite adept when it comes to repairs, I just don't know the science behind combustion too well.

I appreciate any educated answers.

 

Brisk acceleration? (while dropping clutch).

A car will not idle at 200 RPM's. Try inspecting the TB and the DFWS (Don't **** with screw). I do not recommend it, but you can possibly adjust the screw to increase your idle. are those Brk6e- 11's that you are using?

 

I don't usually launch that hard. Don't know what got into me...

But honestly it dips down to the first line on the tach, I can try to get a better video.
Perhaps the tach is not accurate, but either way, I don't think its correct. Afterwards it always recovers to around 800rpm

But yes they are BRK6E-11's.

 

Ok. I would start by checking to see if your tach is off. You can try going in 5th and seeing what RPM you are supposed to be at with the transmission you have. Does the idle feel that low, or somewhat normal?