I guess I'll swap them in the morning while the car is still 2' off the ground and see what happens. Here is the file.

Datalog

 

You've got more than O2 issues. You're computer is reading 3100+ Idle RPM and your Ignition is 0 Volts. Spark advance is 42*.

 

You sure you have the correct definition file for Datamaster. I believe yours should be $EE

 

I have the right file. I don't crank it up until Record #46. Do I know what I am doing? Barely.

 

Swapped the O2s and after it spent about 10 minutes hunting for idle it settled right down. As soon as I have time to bleed to brake system I'll get it back on the ground and and put some miles on it them do some fine tuning. It sure sounds sweet!

 

Its not hunting for idle, for whatever reason it is unable to achieve desired idle and that surging is ignition timing advancing trying to get the engine to speed up. Thats why you see spark advance bouncing around and have an unstable idle. If I had to guess.. you need to crack your throttle blades open because the iac is likely maxed out or some other issue with it, cant say for sure because iac counts are not included in this log.

Your o2 sensors mv looks just fine imo, you're in open loop it starts rich and leans out to stoich or slightly leaner pretty quickly. The crazy crap you see with the rpm and desired idle is normal for key on engine off events and then key off after running. Your o2 sensors are not even being considered until the car is fully warmed over 120F or so and has run for 90-220 seconds depending on the startup coolant temp so the o2's are certainly not an issue here.

 

It ended up beind a bad IACV. Replaced it and all is well. Have 170 miles on rebuild now.