99 Maxima GXE - Rough idle

[Sankrityayan]

It has around 59k. The engine idles roughly, especially after it gets warm; it feels as if it is about to stall, but has never really stalled. I could not feel the roughness at higher rpms when I am cruising.

I got the 60k tune up done along with a transmission flush and a new battery a week ago. Did not seem to help the idling problem. Curiously, when I opened the throttle a bit at a freeway merge the other day (perhaps to around 3800 rpm or so, the SES light blinked a few times, say, for about 10 seconds and then went away. By this time the rpm came down to about 2500 or so that is more normal to freeway cruising. The tech at the dealer could not find any codes and thought it could be because of bad coils. He recommended that I wait for the problem to recur and the ECU to register the exact nature of the misfire so that the bad coil pack can be identified and replaced instead of changing all six of the coilpacks.

A couple of questions for the regulars:

Is SES light (amber color; the right most on the panel) the same as the 'check engine light'?

I have read in another chat session that if the SES light blinks, that is when "the ECU is having a panic attack". So, am I risking permanent damage to the drive train by continuing to drive around without having the problem fixed?

Is there a way to diagnose the bad coil and fix it myself without taking it to the dealer. The price quoted by the dealer is around $120 per coil and I cannot really afford it right now. I am fairly handy and mechanically inclined, but do not have access to special tools like torque wrenches etc.

Thanks for your help.

[lordrashmi]

It seems everyone has this problem. To diagnose which coilpack is bad, you will need a multimeter.

Here is a scan of the page on how to check them.
http://lordrashmi.com/pics/coilpack.jpg

Hope this helps. I had the exact same problem you did.