Just joined the forum today after watching a few of MAY03LT's youtube videos. 2004 trailblazer 4.2. was driving and lost power. (unable to go above 2500 rpm) engine light started blinking. pulled over, and towed home. Initial code was p0300. In the past, Ive had p0302 etc did some tests, replaced coil. Problem solved. This time. Similar tests came up blank. Searched for vacuum leaks. tested fuel pressure. Tested throttle body. Found throttle body motor was bad. (there had been chattering at 2500 for a long time, so I wasn't surprised) Replaced. Watched videos on the subject. I had pulled the number 10 and 28 fuses while doing the work. Not much difference. Still throwing p0300. Found another video stating similar issues and a quick check.The video is rough watch even though it is informative. (Summary-the fuse box mounts were loose) I did have one loose. The bolt housing was loose, but the bolt was difficult to turn. (tight when it shouldn't be) I did turn it in. (everything snug) Started engine and all kinds of new codes were thrown. Here's the list - P0215, P019, P0234, P0357, P0443, P0736, P1143, U0001, U0101, U0106 And then started acting like a bad battery. Even reset my clock. When I'd turn the key to ignition position but not start, the interior lights would dim. Loosening the bolt, helped with the lights dimming, but not the codes and battery appearing dead and starting issues. I'm worse off than I was before. Could a short be the problem (p0300) all along? Any help is greatly appreciated.