Im thinking of freeing up some air flow in my WRX Bugeye Exhaust. At the mo the system is standard apart from a Prodrive Backbox. If I was to change to a third party turbo up-pipe and downpipe and nothing else, do you think it would fail an MOT emmisions test?

Apart from the obvious performance increase would I need to change / alter anything else? A friend said I may have to get a Boost guage. Is this to make sure I dont overboost and come of the pedal before it goes bang?!

Cheers guys.

 

if you are getting rid of the up pipe and down pipe cats,but leaving the centre cat in place i think it should pass mot ok.
it is probably advisable to get it mapped if you are going to increase the flow through exhaust.