1.4L turbo long term fuel trim issue

[Trevinator]

i know this is technically not a fiat, but it shares the same engine so i was hoping i might find someone that can point me in the right direction as to what to look for. i have tried on the renegade forum and nobody there has any clue about anything mechanical with this engine, so thats why im here on this forum searching for help. i have a 2015 jeep renegade with the 1.4l turbo multiair engine and the long term fuel trims at idle and part throttle are in the negatives. when i got home tonight, the LTFT showed around -22 and when part throttle its around -8 or so. when it was working normally, it used to stay around -3 or so everywhere. this is the list of mods i have done to it: forge waste gate actuator, forge vacuum actuated blow off valve, Tork Motorsports stage 2 tune, Tork Motorsports multiair springs, mpx underdrive pulley kit, mpx bored throttle body.

i cant for the life of me figure out why it wants to run so rich! the plugs are black around the ring and its even across all the plugs, so i dont think its a single injector causing it. i have ran multiple fuel treatments through it thinking maybe just dirty injectors leaking by, but it has not changed. i have also changed the down stream o2 sensor with no change. any help with trying to pinpoint the issue would be greatly appreciated.

[Fiat500USA]

I moved this to more appropriate forum to get an answer.

[doverosx]

You’re well within normal specs.

[map]

I'd start by looking at LT and ST fuel trim combined. Your LT in a non-mod'd engine should remain around +/- 5% with STFT jumping up/down with fuel demands. Yep, mods can change the trim values and negative values means your system thinks it's too rich. (I'm not familiar with Tork tunes, but I'd give them a call to check if they mod the LTFT value.)

Outside of owner mods, other causes on cars that can cause a negative LTFT is a faulty O2 sensor, excess fuel pressure or leaky injectors, exhaust leak, low compression, or intermittent misfire (plugs, coils and such)... anything that causes some fuel to not be burned. The risk is the system is leaning way down to compensate (maybe) one cylinder misfiring.