If theres a big vacuum leak, how would i preform fixing it?

 

check your hoses and listen for an air leak, you can spray carb cleaner on your hoses and connections and if your idle drops you have a leak where you just sprayed

 

do as solid GSR YO said and spray some carb cleaner or brake cleaner along all of the vacuum lines and do around the throttle body gasket and intake manifold gasket and even around the little black seals in the intake manifold that the injectors sit in, i've seen those leak before. If the rpms start to raise or it starts to bog, you've sucked in some of the brake cleaner, and you've found the vacuum leak. Replace the vacuum line or gasket as necessary.