Why s my car dragin wen lm moving, its very very weak to pull wen lm driving

Could Be so many many things. It's very difficult to answer these kinds of questions without being at the car. But does the engine rev up like normal but just not go? Or no engine rpm's? Is the CEL on? (Yellow Check Engine Light). Odd sounds? odors? We can try to figure this out, i will watch for your answer. If the CEL is on, first go to a parts house and get an OBDII scan, write down codes and post them.