I did something the other day to mine that helped. Bought a 3/8" OD hose about 3 feet long at Lowes. Removed the air cleaner assy. Started it and put one end of the hose in my ear, the other I moved around all of the gaskets and sensors(wiggled the MAP sensor) listening for a hissing sound. Found two leaks. One was the MAP sensors "bellows", the other was a broken o-ring on the hose adapter that plugs into the manifold that goes to the brake booster.
Runs better and only cost about a buck for the hose. 3 bucks for the o-ring.