I recently swapped a blown tranny and old motor with a newer 2.2l motor and a identical transmission from a different cavalier into my cavalier. The motor and tranny came from a 03 cavvy and were placed in an 04 cavvy. When I drove it the first time all seemed fine, it shifted smoothly and had no problems at all but then I tried to move the gear selector into 1st and nothing happened nor did anything happen when I tried 2 but 3rd worked only sometimes. If I had it in 1st it would only officially downshift into 1st the moment the car came to a stop but then if I tried to accelerate it would never go over 1500 rpm and act like it was going to bog out and die until it hit 25mph then it engaged fully and shifted thro all the gears like normal even tho it was still in 1st