So I had the car off the ground for a oil change, diff drain and changed the spark plugs. After I put everthing back together and started the car up I noticed the exhaust was leaking from right before that catalytic. When I give it gas it sounds like air escaping. (sounds like shit!) My buddy thinks its just the gasket, but it seems to be getting worse. How hard of a fix is this and how much am I looking at? The hsp seems to be lagging as well.

 

If it is a gasket, it won't be too hard to change out yourself. Hardest part will be loosening the bolts, but a little WD40 or PB Blaster should help.

 

ok that doesn't seem to bad. I have noticed a burning smell since this started. Kind of like burning plastic...

 

Did you replace the gasket? You might want to research this issue further. I would first check to make sure everything is as it should be after performing the maintenance you did. Plastic smell could be motor oil or diff fluid burning off. Are the spark plugs torqued down to proper specs too?

 

could be a cracked exhaust manifold or leaking oil from valve cover or distributor on to the manifold.