I posted a few weeks back regarding some rough idling in my LS (06, 3.9 V8) ultimately to conclude that I had a coil problem. Indeed, #4 cylinder coil was bad. I ordered eight new coils, BWD brand, along with some Autolite lridium XP spark plugs. I didn’t find the job too challenging and when finished she purred like a kitten. In fact, I was very pleased with the new found power. A good two weeks went by and then yesterday I went to start it only to hear from the message center…… “ETC engine failsafe”. I also get a message regarding servicing the emergency brake and the little yellow light was on the EB button. The car was idling fine and sounded good out the exhaust but the power was down. I drove it home disgusted and parked it overnight. This morning I went out and fired it up with no ETC message and a fine running engine. What the hey is this? In the past I've had my message center come on regarding the advancetrak only to have that go away too. The advancetrak thing didn't really bother me, but this ETC engine thing scares me a bit. Any thoughts on this? What new surprises likely await me?