Could be the same issue...just hearing it differently. If it's a control Arm, it's not too expensive ($64.90 at Eeuroparts.com), and not hard to do yourself, although you'll have to have an alignment after you're done replacing it. Check the rubber bushings and see if they are cracked or damaged. Also on the older control arms there was a rubber piece on the side of the arm itself...if it's come loose it might rub and make a knocking sound. The other possiblitity that no one has considered here are the motor mounts. Look at the lower ones and see if one or both are loose or torn.