vacuum hose problem?

Start the car and open the hood and move some hoses around to see if you can hear a hiss. This will tell you which one it is. But I might also suspect your throttle body and IAC and EGR valve are in need of cleaning. Remove the carbon buildup with some throttle body cleaner and see if that helps. Search the internet to find how to do this. The MAF might also need a cleaning, use special MAF cleaner for this. The spray cleaners can be found at any local auto parts store.

TOM'S ANSWER REMINDED ME OF THIS. DO LIKE TOM SAID, EXCEPT DON'T LISTEN PULL OFF ONE HOSE, IF YOUR ENGINE IDLE DOESN'T CHANGE THERE'S YOUR PROBLEM. IF IT CHANGES REPLACE HOSE & -PULL THE NEXT HOSE & REPEAT.

There is one sure fire (pardon the pun) way to find a vacuum leak. Use a propane torch, unlit and turned fairly low. Run it along all the vavuum lines and connection, including around the intake manifold. When the idle goes up, you've found the leak.

if you have 1 leak now. you'll have more coming. should replace the lines . its fairly easy. do 1 at a time so not to mess up where they go. vac. leaks are a pain . tom,mike and den's answers are correct also