Hello everyone, first post because I dont know what to do anymore and I need some ideas or if anyone has encountered this issue before.

2006 Evo 9. Tuned on speed density, FP black, ID 1700, 100% E85, 525 hellcat fuel pump, Fuel pressure regulator

I have replaced the front o2 sensor, MAP sensor and TPS

Car was driving flawlessly before I parked it for about 2 week and then next time I drove it the Issue started

Issue is that the car randomly goes rich while cruising, AFRs go from 14.7 to 10.X sometimes pegging the gauge on the rich side. I replaced the o2 sensor thinking it might have gone bad but it kept doing it, so I got one of my buddies to get his evoscan, did some data logging, found that once I would go past 25% throttle the car would tell the ECU to dump about 30-40% more extra fuel for no reason. So I replaced the TPS as a next step, thinking maybe it was intermittently reading wrong causing the issue, and it did nothing the car still doing the same. Decided that before I kept buying and throwing sensors at it, I swapped MAP sensors with another buddy, and while cruising the car was fine and wouldn't do the random going rich thing, so I bought a new one and put it in. the next day the car was running great, but noticed after going on a spirited cruise with some people that it still goes rich randomly when cruising at the higher RPMs while adjusting the gas with my foot, not going to the 10s on the AFR gauge like before but around mid 11s, once id back my foot off the gas just a little it would go back to 14.7 and if I didn't move my foot it would cruise at that AFR without issues.

 

I have the same issue.
I lowered the close loop threshold to 25% load and the issue began.
There seams to be something happening while the car is in open loop and vac is <10inHg and greater than closed throttle
This putts the car into 25% - 50% load on my car in evo scan.
I did bump the closed loop threshold up to 50% and the issue of going rich seamed to disappear due to being in closed loop till > 50%

 

Did you do a boost leak test?

 

I did, it holds boost perfectly fine, even did a smoke test to see if lines were torn and everything was solid