First off... 97 xtra cab zr2 4.3 5 speed.... Started out as my rpms didn't want to drop when I pressed in the clutch to shift gears, was staying around 2000 or so. So I had a ses light anyway so I took into my buddy's shop. He read the codes and got an iac and an o2 code. No problem. Got all 3 o2's and a new iac valve. Installed and did a drive cycle as recommended which was driving at 40 mph for a few miles so the new iac could learn. Since then the rpms have gotten worse... Now it sticks at 3000 plus rpms and won't go down unless I press the brake pedal down to the floor!!! I'm not kidding, that's the only way to get them to drop!!! Hitting the gas just makes it worse!! The bad thing is that it doesn't do it all the time, about 70% of a 7 mile city driving trip( the drive to work). I went out and got a full quality tune up kit... Plugs, wires, cap, and button. Runs better but still no change with the rpm issue. We even went as far as disconnecting the cruise control to see if that had something to do with it, lol!!! My buddy, 2 of his good techs, and myself are out of ideas.... We are gonna do some vacuum testing tomorrow and see what we can come up with but other than that, we are at a wall... Please someone chime in and say you have heard of this problem before, lol!!! This is my daily driver because my srt8 charger is at arrington performance in va getting dyno tuned till god knows when....... HELP!!! Also, I forgot to mention that while driving, if I let off the gas the truck will hold its speed as if the cruise is on but the cruise is not hooked up at the moment.... Kinda unsafe, ya know??