KatieinOregon

I have always noticed that when the vent is open and the fan on that my subaru will suck bad smelling air inside when I pull up behind an exhaust heavy car. I am getting that now all the time. It doesn't seem to happen when I have the air-conditioning on. But if the vent is open -- even with the defroster on. It makes me think the smell is coming from my own car. I have new tires -- could that be causing it? or should i be looking for something else? I just recently had a bad problem with a tire (which is why I now have new tires). There were warning signs but I didn't pay enough attention. I don't want to do that again. There are no other signs of a problem. KatieinOregon