where does this 2 goes?
 

after i installed the racing beat exhaust i find that there are two exhaust plugs that are shouting air out
if anyone know plz tell me what do they do thx

and will they cause vaccum leak?

Air injection ports.
The one in the back goes to the cat and the other is the bypass which leads to an external silencer on the 2nd gen....on the SE I think it goes to the aircleaner box.
Neither are needed,nor is the airpump or ACV if your not gonna smog the car.Just go to the Mazdatrix site and order(or make) some block off plates for the ACV and EGR valve.Youll never pass smog again,but thats how you deal with smog control gear when installing a CA illegal exhaust system......