a4 quttro problems

[bigbadbucks]

hello i have a 99 Audi a4 quattro sline i bought the car cheap so i no iv got to spend abit of cash getting it in tiptop shape. I had a garage put the diagnostic computer on it and it came up right rear wheel speed sensor so i had that replaced at 114 pound for just the part but still the abs light is on can any body help

and when i put my foot down after just cruzzin along at [just say 30mph] jumps and shuders like it wants to cut out what would that b