Bigd08ffc

Hi, ive got a mk1 focus on an 03 plate that has an idle problem..... it idles very erraticly and i was told it was the idle air valve... that has been changed but it still has the same problem, any ideas?? it feels like it will cut out if left idleing and stutters, also on the top of the rocker cover not where the 4 holes are for the plugs but the centre hole with a cable coming out has a leak, any idea what the bung that goes there is called so i can order a replacement?? cheers guys