so a 97 legacy brighton 2.2 wagon 5spd, No loud sound coming from the exhaust just a lot of fumes in the car when its parked, not rotten egg smell,not syrup, just good ole exhaust fumes. Cant seem to figure it out, no codes, running good, just cant nail it down, it does however have a whistle when you punch it for around 3500rpm-5000rpm so I thought that may be the culprit some leak underneath. All the vaccum lines seem ok, maybe check the EGR or PCV?:-\

One way to make exhaust leaks easier to find is to obstruct the tailpipe temporarily while checking underneath -- I use a wadded-up old cotton t-shirt, held against the end of the tailpipe (not stuffed into the pipe). I find it's best done with two people, one to hold the "T" in place while the other looks/listens for any leak. Exhaust backpressure will tend to push the "T" away, and even if there's a leak exhaust will get past it, so the person at the tailpipe shouldn't stay there for very long.

 

If there aren't any exhaust leaks, the smell might be from leaking oil, etc., getting on exhaust parts and burning there.

so a 97 legacy brighton 2.2 wagon 5spd, No loud sound coming from the exhaust just a lot of fumes in the car when its parked, not rotten egg smell,not syrup, just good ole exhaust fumes. Cant seem to figure it out, no codes, running good, just cant nail it down, it does however have a whistle when you punch it for around 3500rpm-5000rpm so I thought that may be the culprit some leak underneath. All the vaccum lines seem ok, maybe check the EGR or PCV?:-\

 

there is a donut gasket with spring bolts just after the section with the cats and before the mid-pipe, look there.