is a forge split r dump valve.

and the blanking plate has come out the back of the turbo, get another 19mm nut to put in it

what's actually meant to be in there then coz im sure a normal nut cant do the turbo any good????
 
looks like some1 has a new user name! blanking plate of the back of the turbo? at a wild guess is this were the egt sensor should be?
 
any 19mm bolt will do it mate, when i had it there was a wheel bolt in the back, it blew out once in the 2 months i owned it, i then put another nut in job done, i did not do it up tite tite as i did not want to strip or crack the housing as that would then be caked!

you have my number mate any problems in future ring me rather than post on here as i can answer it there and then :)