Long story short, here were the original issues... 1: Check engine light was on. 2: Got messages for "check fuel cap" (I couldn't completely fill the car up with fuel) and "check charging system". 3: Sometimes the AC would blow cold air, sometimes not. It was random. 4: Car would have hesitations and stalls at low RPM, like when I was turning, or accelerating after being stopped at a light. Almost felt like there was no fuel getting to the engine, or maybe there was an air flow issue. One day it stalled out completely going to the office, and I had to turn it off and turn it back on in the middle of the road. So, I went and got it checked out, and as it turned out, the alternator was overcharging the battery. So, I got a new alternator. That seemed to fix everything, and it has turned out to completely fix the "check fuel cap" and "check charging system" issues. But not the others. The next day, I was having some of the same issues again... 1: Check engine light is on. 2: Slight hesitations, though nowhere near as bad as with the bad alternator. No more complete stalls. 3: AC sometimes blows cold air, sometimes it doesn't. So, I took it back, and they ran another diagnostics check, and it said I needed new O2 sensors and a new mass air flow sensor. Sounds right...I thought an air flow issue might be the trouble anyway. Also, recharged the AC, filled with Freon, also got the radiator cleaned out totally with brand new fluid (I know that part of it needed to be done). Another $700, after $400 for the alternator. So I get that done, and everything seems to be working fine. The check engine light is not on. The AC is blowing really cold air. Don't notice any hesitation. Sweet! It's fixed. NOT! The next day, the check engine light is back on, the AC is sometimes working and sometimes not working, and there is still a very slight hesitation sometimes when I hit the accelerator after I slow down to turn. Not all the time, but sometimes. Nothing major, but enough to be annoying. Doesn't happen when I'm rolling at 75 on the interstate. Only when I'm changing speeds a lot around town, and even then not all the time. I feel like I wasted money on new O2 and mass air flow sensors. I know I needed the work on the radiator and new Freon, etc. Clearly the new alternator was needed, since it knocked off the "check charging system" and "check fuel cap" warnings. Any ideas? I feel like it's something electrical. Somebody told me it could be the smart junction box (which I think would be another grand, sheesh). I guess I'll call Shelor later and get a Ford specialist to look at it and run a more specific diagnostics test, but apparently I'm looking at a 1.5 week wait right now. Thought I'd run it by yall to see if you have any ideas.