So the other day I was out for a drive and everything was fine. I was cruising along and came up to a stop and the car stalled when returning to idle. No big problem here as I am running the CatCam on a early model ECU (ViPEC is in the mail).
So I restart the car and it dies immediately (usually it will idle on startup no problems) so i try it again. Dies. So i crank it with a little pedal pressure on the gas get it to rev but it sounds like it is only firing on two cylinders.. but here is the thing.

It sounds and acts like it is on a constant missfire
AFR is showing 8-9 (super rich, usually at 14.5-15.2!)
and this problem goes away WHEN I FLOOR IT!
Hard acceleration is still okay.
-AFR comes back in line, and car runs smoothly at WOT.

The short term fuel mix looks fine as well as long terms (both at ~0), and I have tried resetting the ECU.

I did just fill the car up the night before with gas from a station in a small town (not sure how fresh the 93 octane gas was)

The car often cranks and idles fine now, chugging along at 14.7 afr. Can even get it to rev fine. As soon as I put the car in gear and load the problem resumes.

Car throws missfire codes (duh!) and at one point gave a primary circuit A and primary circuit B igniter code (both banks of wasted spark).

I have had the unstable idle issue for a while (even before cat-cam install) and just read somewhere today that it has to do with a purge valve on the emissions system. (is this the fuel vent valve located next to the S/C outlet horn? or the vent in the tank for the leak system?)

Any insights would be much appreciated.

Currently have bytetronic. I also tried re-flashing the ecu to a prior tune to see if it made any difference. No luck.

 

Also recently replaced:
- Crank position sensor (a few hundred miles prior)