PCM Diagnostics & Tuning - tune getting worse?

Hey guys, so I picked up my Camaro last year. it is a cam only car and was tuned by the previous owner. The car had always had some weird idling issues, high idle ect. But it has continued to get worse and worse until the point were it won't idle by itself cold, it surges up and down, pops, misfires until warm. The IAC wanders and went let the motor rev down even remotely quickly,.if I unplug it it does a lot better. My question is should I be looking into the tune which has always been weird but is now unbearable or looking at a sensor or other issues even though it isn't throwing any codes.

The tune didn't change. [If it was messed up when you got the car, it still is.]
Something else going on...
Vac leaks.
Fuel psi whacked.
A sensor[s] gone nutz.

Until you scan it, do some data logs, and post the tune, it'll be difficult to avoid guessing and throwing parts at it.

And, it may good to post some info about the car...;)

A good tuner can make a cam car idle just fine. The tune is jacked! There may be something else going on adding to the problem but it needs tuned.