Downpipe cracked/Blowing
 

As title really. M.O.T coming up, just had a general checkover of car and there's a fairly large blow coming from under the shield by the standard downpipe. I can't get under the shield to see as the bolts are coroded to pieces.
Is this a common problem? Any idea's on fixing other than replacement?

for a quick fix, you can buy an exhaust bandage from halfords, just wrap over hole, will pass mot no worries, they cant fail it if its not leaking