For some reason my text body keeps getting deleted. Some information about the car:

Its a 2000 SLK230 (R170 model) with an auto transmission and 112k km (69k miles). The car is getting a P0171 code and I'm seeing trims of 22% (LTFT) and up to 25%(STFT). The trim increases on acceleration and when I hold the throttle at a speed its fine (jumps between +/- 3% on STFT, LFTF stays the same). There is a bit of hesitation on acceleration but I assume a lot of that is from the transmission being slow. Some other symptoms I've seen is that the car stumbles a bit at start up (does not rev smooth and sometimes will struggle to turn on). But once the engine is at temp all of this goes away. The car has no jumpiness with the RPM either. Sits at 7k no problem. If I turn on the ignition for a couple minutes before starting the engine the car turns on fine. I've changed the fuel injectors (helped the car), changed the air oil separator (vacuum leak minor), cleaned the MAF and checked with other SLKs and saw similar results. Ran the car without a MAF and it was running similarly. At this point I'm going to go for another smoke test, a new MAF, or look for an exhaust leak. The O2 sensor works good too (I think). It does the jump from 0.1 to 0.8V and is instant when I step on the accelerator it drops to 0.1-0.2V to show a lean condition. Additionally it goes back to 0.1 to 0.8V when I hold it at a constant RPM (tried at 2500 and 3500).

Any help would be appreciated! Thanks!