1971 Duster exhaust smell in cabin after new muffler and tail pipe

Hello all,

My 71 slant six duster's muffler was noisy, buzzing and rotted through, so I took it to a local exhaust shop to get it replaced.

They replaced the muffler and tail pipe. I paid and left. Within a couple miles the air in the cabin felt stuffy, thick and my nasal passages started swelling. I thought maybe the car in front of me had exhaust leak. Long after I passed him I still felt like the cabin had a low but constant volume of exhaust making me feel sick. I took someone else for a ride, they smelled exhaust too. Windows up or down.

I looked underneath the car and noticed the end of the new tail pipe looks like it's at a different angle than the original pipe, like it doesn't have the same curve. It also seems like it's tucked under the car more, and doesn't extended out towards the bumper as far as the original did.

Can someone confirm or post a picture of where the stock pipe ends? My suspicion is that my new tail pipe is not long enough, and/or not curved toward ground enough, and exhaust is being pulled back into car.

This was not happening before I had the work done. And currently I don't hear any audible leak, so that's why I'm focused on the tail pipe theory. Also, my exhaust manifold heat control valve is frozen, but I don't see how that could cause an exhaust leak into cabin.


Here's a pic of new pipe


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CHANGE SHOP