It sounds like a hair buzzer but much more vulgar. I looked and there is no donut gasket. This is a 2.5l 1999 4 banger. It does not have an manifold leak. I stuck a vacuum in pushing air through and did the spray soapy water test. There is one small leak where the manifold meats the down pipe-but very small bubbles. I think its a broken catalytic converter but what do you guys think?! Here are some sounds of what it sounds like.
