weird brake booster issue and idle problems on redtop

[slave]

Ok, so I'm tuning my sr after installation, and at idle, after the car warms up a bit it starts to run a little rough. Not very much, just enough to be noticable. When I rev the engine in neutral, it revs fine, then, when I let off the throttle, it drops down well below idle rpm, almost killing the engine, but then the engine jumps back up to idle rpm and runs fine (besides the slight roughness). Think maybe either of these may be the o2 sensor (just a shot in the dark)? Also, when I pump the brake, it starts to kill the engine, and the more I pump them, the lower the idle drops until the engine almost dies after about 3 or 4 pumps. Any ideas?

[cdlong]

i bet it's another vaccum leak. the extra air from the booster is just enough to kill it (or almost)

try looking around for other vaccum leaks, a way to make it easier, let the car idle and spray starting fluid around the connections. if you hit a leak, the engine will rev.