I have a 1999 Forester, 2.5 engine, which has an exhast smell coming into the interior when the "outside air" circulation is on. The muffler and pipes have checked out fine. The car had the transmission re-built 6 months ago and I'll wondering if removing and installing the exhast system during that repair, has caused the problem.

I don't have a direct answer to your concern, but did you read the post by "Forester air recirculation problem" ??dalecherokee

 

 

It is worth noting that you're the second owner to post an "exhaust odor inside vehicle" concern within a week.......although you mention yours occurs in the "outside air" mode....

 

Is the exhaust system on your vehicle damaged/modified in any way? Has the vehicle been put up on a lift by a technician to have the exhaust system inspected? Have you looked at the tailgate and tailgate surround weatherstrip (as I suggested to dalecherokee) to make sure the gate closes/seals securely so that exhaust isn't sucked back into the interior? A leaking manifold gasket can be HEARD, especially under acceleration. Starts out as a "ticking" under acceleration..........

 

 

I have a 1999 Forester, 2.5 engine, which has an exhast smell coming into the interior when the "outside air" circulation is on. The muffler and pipes have checked out fine. The car had the transmission re-built 6 months ago and I'll wondering if removing and installing the exhast system during that repair, has caused the problem.