Firstly, I appreciate all the responses.
It's shifting into 4wd.
On my list:
Check timing
HGs
Compression
Since I had already ordered the CTS part, I put that in there and that seemed to have fixed my issues. It's running like it was before and it's driveable again.
It was really strange symptoms and it happened randomly one day and never stopped. Could the overheating have caused the very old CTS to fail somehow?
Since it was doing the same thing with the old CTS just unplugged, I figured maybe I wasted money but there was seriously a lot of threads on here with people having failed sensors. Their symptoms sounded exactly like mine. I'm happy at least it will drive now.
Another problem:
When I bought it, it had a very low idle. You can hear a weird faint popping sound from the tailpipe every few seconds. The car shakes but it doesn't bother me. The tailpipe sound and shake go away with a little more RPM. It's back to it's current state with a low idle, but it doesn't stall or sputter.
Adjusting the idle speed screw seems to have no affect.