So I just picked up a 97 camry. 134k on it. I am having a slight misfire at idle. Only when in drive at light and the brake is on. As soon as I put it in park, the idle is perfect. But as soon as its in any gear, the idle is steady, but then misses ever few seconds. I am hearing a air leaking sound, from the engine bay, every time it does it. I have checked all vacuum lines. maybe pcv? I know plugs and wires could be it, but personally, I have never solved any automotive problems by replacing plugs and/or wires.

Thanks,
Anthony

 

Have you checked the brake power assist can for leaking? It uses vacuum from the manifold.