Engine Misfire

[jt217]

Ok here goes with the Symptoms. When my car is idling there is a sight misfire. The problem gets significantly worse at normal cruising speed but stops under acceleration. I suspect that it is related to a vacuum problem due to the problem starting within days of me installing the boost gauge. I checked my spark plugs and they were clean and properly gapped. Only other thing that has recently changed is the wideband 02 sensor that I welded in. Can anyone offer a advice on what I should check? I have checked for a vacuum leak but that doesn't mean there isn't one. (by no means am I an expert) mods in sig if anyone needs to know.

 

[jt217]

Also another question can running to many accessories off the vacuum line(boost and bypass from supercharger) change vacuum pressure enough to effect drivability?

 

[lime 05]

hook up a vaccum gauge on a vaccum port and it should be about -20.