Exhaust fumes in cabin....details below
 

Hello all. I've got a 2009 lancer gts. I've currently got around 135K miles and have had exhaust fumes entering the cabin. I initially thought this was from a leak, and eventual break, in the exhaust pipe past the cat, but this has been repaired and is still happening. Any help is appreciated. Here are the details:

1. No check engine light
2. Happens when using heat, A/C or vent (basically whenever the blower is on)
3. Usually bad at idle (car not moving or parked), but is much less to non existent when moving/driving
4. When trying to see if I can find the leak, I can smell exhaust fumes between the back of the engine and the firewall
5. When the exhaust pipe broke, the system from the cat forward did hang down until I got home to quick fix it. The seal from where the exhaust header connects to the rest of the exhaust pipe was replaced when I had the break repaired.

Thanks again ahead of time. Let me know if you need any more information.

Same issue with 95 Diemante ES.
 

I have the same issue. All leaks have been fixed and no vissable leaks can be found at this point. I've replaced all gaskets and still can't find where the exhaust is getting in the cabin? It's also only when the blower is on and also the same, it's worse when just ideling. Any suggestions?

Same issue here too. One additional clue on my Mitsubishi Endeavor. The fumes do not come it if I turn on the "Recirculate Air" button. So, when the heat/blower is on and pulling in outside air it also pulls in exhaust. Wondering where the air is pulled in and if that can lead me to the leak?