I just threw my head back on with new gaskets and it runs with no CELs, but it would shoot to 2000 RPM right on startup and there was a hissing noise from around the throttle/manifold. I moved the intake and snugged down the throttle body bolts really good and was relieved to have a more calm 1450 RPM on startup. However, the hiss is still there! I felt around and it's right on the MAP sensor/TB mating surfaces. Also, the idle seems to drop when I wrap my hand over it the right way (though I don't know to what as I'm working alone). Here's the kicker; the MAP sensor was never previously removed from the throttle body and it also won't snug down any more without stripping the screw heads. Anybody know where I should start?