Did not remove TB, but the gasket was done about two weeks ago. Im not sure how these TBS work, but I dont think so because it will only do it at a dead stop. I tried switching the brake booster to the other vacuum line port. Runs better and think it is right now, but I still have the issue.

 

That is true for 96 and earlier. He has a 2001. Passenger side is airbox, and drivers side is intake.

I know because i had a 1996 and now I have a 2001.

 

+1 for locations on a 2001.

 

i know that there are two different versions of the stock intake.
my 99 5.2 has the breather valve onthe passengers side, while my bros 01 5.2 has it on the driver side

 

My truck has the same problem. It also developed after the plenum switch. My brake booster goes directly to the manifold. The driver valve cover goes to airbox, and passenger valve cover goes to manifold. I think my problem my lay in the vacuum tubing on has the T on the pass side of engine.

 

here's a thought. What if you/we didn't seal our intake manifolds well enough and there's a small leak into one or more cylinders?