Hello, ok so Ive had my Merc for a little over a yr and half, I picked her up for a grand so the fact the power windows, monroof, 3rdrow seat, horn, adjustable pedals and drivers seat position controls didnt really seem like a big deal. The ac not working did but considered it a fixable deal considering it just blew hot. She was mechanically great no complaints. After awhile I noticed gas mileage not doing getting worse, again nothing major. I bought her fairly close to her 189k servicing, so I too her in did the whole fluids and filters change. I figured she was up for plugs and O2 sensors were probably ready but didnt swap at that time. A couple months later, she starts stalling coming to stop.I threw her in neutral in advance but still stalled, she would start right back up and I was on my way home so I kept going. This repeated about 6 more traffic lights then she didnt want to start another time. It almost seemed like a dead battery or out of gas situation. Luckily I was close enough to house and boyfriend pushed me in yard with his ford. She has been sitting 9mo crank no start. I did get it to start a few times but would quickly die Pulled codes few times all were U and B codes with only 1 P. Recently ,I did get her to start and run held idle just fine until I dropped her into drive died instantly. So changed fuel pump 2nd time. Her new battery was now bad couldnt tell if it fixed it. sat another 2mo no batt in it, got one in and back to crank no start exactly like before it finally started. Now the OBD is no longer reading, cant retrieve any codes. Below I listed whats been replaced, dtcs I had pulled in last 6mo.Any opinions thoughts or help is greatly appreciated, thank you so much

06 Mountaineer Premier 4.6 AWD @ 201K
NEW; BATT, ALL 8 PLUGS AND COPS, TPS, FUEL PUMPX2, FUEL FILTER; FUEL PUMP DRIVER MODULE, BOTH CMP'S, CKP,
ALL FUSES CHECKED AND GOOD ALL RELAYS TESTED AND CHECKED OK.
FP@ RAIL 32 (cranking)
DTC'S: B1203, B1318, B1681,P2290,
U0100, U0140, U0159, U0208, U0244, U1900, U0203

*NOTE; MY MERC HAS NO RUNNING BOARDS AND REARVIEW IS REPLACED WITH WIDE VIEW 4 PANEL TYPE