1993 rx-7 pob
 

I just bought a 1993 mazda rx-7, everything is stock except for the mufler, i recently started to notice a power decrease over time for the last month, the boost meter was not puting out the normal amount of boost, and i started to hear the blow off valve, before i never heard it, then when i got off work today i opened the hood looked at it and noticed that when i reved up the motor there was a small amount of smke that came from where the turbos are. anyone have any tips for me, this is my first rx-7 and i tried to find a service/repair manual for it but i found nothing. If anyone has any tips over it of might have a good idea what the prob is feal free to leave a comment. thanks