OFF cruise, rich condition

Heyo,

I have a 10' Evo SE with the following related mods:
Tephra v3
91 Octane 0% ethanol
ID1700's - just cleaned & Injector Dynamics with 0.9% spread among all 4.
450lph pump
AMS Big Bore 2.2L
AMS Kelford Cams
Fuel lab adjustable regulator set and tuned at ~44 psi
Generic newish K&N filter over 3.5" intake
Idle LTFT ~(-5%) changes with weather slightly.
Cruise LTFT ~ 3%

I've had a condition start occurring where anytime I come to a stop, AFR idle comes to around 11-12 and holds, almost like it's open loop. It takes about 5 seconds for AFR to dial back into 14.6 before it does its happy dance to maintain stoich. It causes no idle problems, and it seldom goes lower than 12. At cruise it has no problem hanging around 14.7 with only a few % trim in either direction. I would just like to minimize any cylinder washdown as much as possible. If I hold a free rev for a few moments, then let it fall back to idle it will also do the same rich-hold for a bit before going back to normal. My WOT fueling has not shifted lean or rich at all.

Has anyone encountered anything like this? Is there anything in ecuflash I can modify to adjust this? A little confused as to why I'm getting so much fuel when the engine is returning to idle. I know the injectors are massive to be idling on pump gas, IPW is between 0.9 and 1.1ms, but this only started last month.
Otherwise the car runs great, no pops, smoke, surges, etc.

Any insight would be appreciated, thanks.

 

Think it's just the cons of running large injectors on pump gas. My car does the same thing on id2000s. You can try to lower the ipw but too low a number will prevent the injectors from behaving properly. The ECU is doing it's best to pull fuel in closed loop. Some people get around it by just running open loop. You can try raising the idle or lowering your base fuel pressure but I believe it's just the nature of the beast.

 

Thanks for the input, I'm just looking to optimize anywhere I can. If that's how it is, then that's how it is.