[baritone_mike]

What causes this? It does not smell like eggs or oil, it is just a stong exhaust smell. I have no exhuast leaks and cannot smell it in the Jeep unless I have the top down or a window down and the wind blows the right way when I am stopped. My Jeep passed emissions two years ago but I think the smell has gotten worse. My exhaust is loud which I guess is not normal for a Jeep, and it does burble on down shifts and engine braking (coming down from 2,000-2,500rpm) and I ocasionally get a pop/puff sound from the back of the Jeep during the shift after a long uphill drive at a little above 2,500rpm. My Jeep is not lacking power (insert 4 banger joke here) and I got 16.5mpg last tank so I think it is running fine. I am just curious as to why it has a strong exhaust smell.

[CB10101]

How is your tailpipe positioned. Mine used to come straight out the rear and if the back window was rolled up the exhaust would come into the jeep. I've since, turned it down and its not nearly as bad.

The gurgling and popping while shifting sounds like you may be a tad rich and detinating in your exhaust.

[baritone_mike]

The tailpipe is turned down, but I still get the smell inside of the Jeep with the back window rolled up. The thing I don't get is if my Jeep was running rich then wouldn't I have bad gas mileage? I am getting between 15.5-16.5mpg on every tank which is not bad for 33's and stock gearing all city. I put a new O2 sensor in it two years ago (only 8000 miles ago) along with spark plugs and wires.

[NonRubicon]

When the back window is the only opening into the cab, you are going to get some of the exhaust drawn in due to air flow. The boxy shape creates an eddy which picks up the exhaust. With the rear window rolled up, some of that exhaust air gets pulled into the cab.

If your fuel economy hasn't changed then I wouldn't expect the problem to be due to running rich; but, you could be slightly rich so if you can check for codes that would be a place to start to rule that out.

It could also be a bad catalytic converter. A bad cat won't always smell like eggs, but you'll probably notice a richer odor due to unburnt fuel not being catalyzed.

[baritone_mike]

I know the back window pulls exhaust in, but I don't think with the top down you should be able to smeel the exhaust if the wind is blowing.

My Jeep does not have a check engine light so I don't think it will have codes to check. If anything my Jeep seems like it has more power and better fuel mileage then it used to.

My cat is probably going if not gone, it has a rattle and my Jeep is louder then other Jeeps and I think I have stock exhaust.

[Que89YJ]

The smell is either bad cat or bad control. O2 sensor is new so I would try the engine temp sensor, check your exhaust manifold VERY closely for and cracks or loose bolts and last but not least the cat.