2009 volvo s40 2.4i engine problems

[1616samson]

I bought my car from the auction 6 months ago, witch apparently has a salvaged title. After fixing the car i drove about 1,000 miles on it, and it started having engine problems. The first problems that started were, when i put the car on drive, and start pressing gas it would make some kind of a stumbling move and then continue driving, and also when i would press on breaks rapidly the engine would just turn off, but the power would still be on. Now the the car has a reduced engine power note on the odometer, and when i turn on the car the rpms go almost 2 rpms, and it sounds as if some one is pressing gas, and also when i try to drive it it only goes 20mph and no more. Please help anyone!