cacahead1

i have my wastegate set at 12psi. i recently rebuilt my turbo so i took off the manifold too, when i put the turbo back in i didnt have a boost leak. so its a month later and know when my vtec engages i lose boost 3 psi to be exact. can anybody help? think i should replace the manifold gasket? also i didnt replace my gasket but at first it was ok no leak