All of the sudden my 1999 328i started running bad

all of the sudden my 1999 328i started running bad idle irratic, dying ect. so i changed the fuel filter no change. i hooked up obd and got several codes. ended up replacing throttle valve,mass air meter,air boots,all hoses and intake gasket. new plugs and wires also. now it only does it every 3or4 times i start it but i have new codes and no power at all unless i floor it and it takes a while long lag in acceleration. new codes are101-340-412-1781 and my trans light just came on. this car is just a ton of problems. 3 mos ago replaced timing chain, water pump and belts and co sensors. 120000 miles the shops all have a different answer. where should i start? oh and i have replaced gas cap,battery and thermostat.car was running perfect before rough idle problem and now it seems to be going down hill no matter what i throw at it. for one day after repair of gasket and all hoses etc i had no codes but ran like **** any ideas?