Been having this problem since I got the truck. There's an exhaust leak on the right manifold, haven't dug in too far to find it. When I'm driving with the windows up and the A/C on, I'm getting exhaust fumes through the A/C ducts. I put silicone on every joint in the evaporator box and around the blower housing. I know this is where some of the fumes were coming from because when I ran the air for the first time after putting the silicone on, I could smell the silicone in the A/C. Is there anywhere else it could be coming from?

 

forget the silicone. fix that exhaust leak right away.

 

I agree. Get that leak fixed.

 

I'm getting ready to install headers and custom exhaust, so I'll just do it then. Should be real soon. I'm doing the custom exhaust work myself... we'll see how this turns out.

 

ok good, you dont want those fumes leaking in the cab, especially before the converters.