This is just what I've done before figuring out what the root problem was, any help would be great! (Post 3 is where I found out my issue)
OK, this is bothering me.
I unhooked my o2 sensor via opensource so its running in OL all the time. I started off with a 16 A/F when the car was fully warmed up and idling. I then proceeded to scale my injectors (1100cc original, slowly decreased value) and got the car to 14.2 A/F. Alright so I was getting closer to 14.7. Now I continued to scale my injectors (increase value to lean). Fired up the car and boom. 11.5 A/F. Reverted back my injector scale and nothing, still 11.5 at 800 rpms. If you gave it gas and maintained the throttle position (1100rpms) the car would be fine. 14.7ish A/F.
This was only decreasing the injector cc scale.
This doesn't happen all the time. Its weird and random. Is one fuel injector going to town ie stuck open?
Come to think about it, my car has been doing this for a while but the o2 sensor was compensating as I see it going for 11.5 to 14.7. I also noticed it going rich during a WOT then letting the car cost to idle.