ive got a 1.6 cvh, on the exhaust its got 2 box's. the backbox and a little one.

im changing my backbox to a different one would it still run fine and go through mot's if i took off the little box off while im chanhing the backbox

 

THeres nothing you could do to the exhaust to make it fail an MOT, apart from make a leak in it

 

a bit riski m8 but if you do a good job it would pass if your emitions are low enough