Vaccum lose Question.

Hi I have a GSX 99 with a vaccum gauge. I had 20-21 hg vaccum and now I put a 3inch exhaust on my car and now I have only 15 hg on my gauge. Is this because of my exhaust or is that another problem. Sine I installed this exhaust my idle runs lower also.
Thanks

Make sure the exhaust is tightened down all the way in all areas, u might have an exhaust leak. Does it sound loud like a tractor in parts of your car?

Hi, no its quiet but loud behind. I think there is no leak. Could it be that is because the exhaust let pass more air than the stock one ?

I have a hi flow cat, a Vibrant Resonator and a Dynomax Turbo Muffler .

Thats odd because my vac actually went down when I installed my exhaust, check for vac/boost leaks

Thats odd because my vac actually went down when I installed my exhaust, check for vac/boost leaks

His did too.