2001 blazer 4.3l gradually has been losing power. Now it still cranks but any pressing of the accelerator bogs it down like it is starving for air. Sound gets very loud at the air filter. Last couple days would Rev to about 2k rpm and stay there a second or two and with accelerator to the floor would slowly drop rpms and almost die. Now any throttle at all and it bogs and dies. Have a pic of a vacuum hoses that is disconnected and can't find where it goes. Wondering if it is related first of all, then still need to know where it goes.