Hey everyone! I've been stalking this forum for about a month now since buying a 2004 Trailblazer LS. There is a TON of awesome info on just about anything I need, and even a bunch of videos. I used several of these resources to change my spark plugs and clean the throttle body at about 91,500 miles. The throttle body wasn't horrible, but definitely needed a wipe down. The plugs were worn and needed the change as I thought. Now the truck idles much smoother, even when cold, and the throttle response is improved along with the power. It also seems to fire up quicker. It was definitely a worthy project for $50 worth of parts and what not. The only things I had trouble with were removing the coil from #1 (bumper end) and finding some oil on the threads of #6 (firewall end). I don't know everything about car design, but whoever decided to place that wiring harness immediately over the #1 coil needs to be beaten to death. They could've moved the harness 1 inch up and there would be zero problem. Other than that it was a very easy job, even on the #5 and #6 under the firewall. What do you guys make of the oil on the #6 threads? I've heard it could be a worn piston ring, worn valve covers, and/or harmless fuel deposits that occur sometimes. I really can't spend hundreds of dollars to fix anything right now unless it is absolutely necessary. Any feedback would be helpful. Thanks!