I know this probably doesn't belong here but before I go make a new login on a trailblazer forum, I thought I'd ask. 2006 TB LS, 131K Miles. Issue #1: 4X4 system engages intermittently. Sometimes when I shift to 4x4 the indicator says it's in 4, but I know it's not in 4. Also, sometimes when I go to put it in 4x4 the indicator lights will flash and then it will pop up a big red N light... Issue #2: Rough idle/dies at start up. When I start the truck up cold, it idles poorly between 500-1,000 RPM, and sometimes it will actually die. It feels kinda like a vacuum leak, I had one of those once on my old Tahoe. I cleaned the MAF and put a new air filter on it but still does the same thing. Any help? Thanks.