Got the high flow cat

[Porch]

So, recently did the rawtek dpf/EGR delete, malone stage 1 tune, no resonator or cat, straight pipe back to the factory muffler. The gains in drivability, performance, and mpg were fantastic. But the smell was revolting. Like, unbearable. Couldn't drive with the windows down, couldn't open the tailgate with the engine running, all my clothes reeked of exhaust, etc etc.
So just got the high flow cat installed, the sale of the dpf and big factory cat paid for that plus a little extra. The cat makes the exhaust much more tolerable. I still wouldn't want to stick my face right in the exhaust, but I've never met a car like that, so whatever.

My question is, I'm still getting exhaust smell in the cabin at times, most often when the AC is on. Usually, when I turn the ac off but keep the fan on, smell goes away. It also tends to smell when I'm in gear but decelerating from speed, and when I come to a stop from speed, like one of the off ramps on my farm. Supposedly, the exhaust is tight, I asked my mechanic to double check when he installed the cat pipe, so I have no idea about the AC isuue(neither did he), but as for the other stuff, I suspect it's just aerodynamics- the back of the car gets super filthy from road grime getting whipped up by the turbulent air behind the car, so I suppose the exhaust is getting caught up in that as well, and leaking through my tailgate... anyone else had this kind of issue in a JSW and figured it out?

 

[DivineChaos]

Check your manifold for any soot. Check your turbo to downpipe, that leaks quite often. And then check all your exhaust connections to make sure there's no soot.

So, recently did the rawtek dpf/EGR delete, malone stage 1 tune, no resonator or cat, straight pipe back to the factory muffler. The gains in drivability, performance, and mpg were fantastic. But the smell was revolting. Like, unbearable. Couldn't drive with the windows down, couldn't open the tailgate with the engine running, all my clothes reeked of exhaust, etc etc.
So just got the high flow cat installed, the sale of the dpf and big factory cat paid for that plus a little extra. The cat makes the exhaust much more tolerable. I still wouldn't want to stick my face right in the exhaust, but I've never met a car like that, so whatever.

My question is, I'm still getting exhaust smell in the cabin at times, most often when the AC is on. Usually, when I turn the ac off but keep the fan on, smell goes away. It also tends to smell when I'm in gear but decelerating from speed, and when I come to a stop from speed, like one of the off ramps on my farm. Supposedly, the exhaust is tight, I asked my mechanic to double check when he installed the cat pipe, so I have no idea about the AC isuue(neither did he), but as for the other stuff, I suspect it's just aerodynamics- the back of the car gets super filthy from road grime getting whipped up by the turbulent air behind the car, so I suppose the exhaust is getting caught up in that as well, and leaking through my tailgate... anyone else had this kind of issue in a JSW and figured it out?

 

[JELLOWSUBMARINE]

Sounds like a "smoke " test would expose any exhaust system leaks.

If you're not familiar, it blows smoke into a sealed off area, in this case the exhaust system

 

[ZippyNH]

Aww....now you understand why emissions systems created a QOL improvement (both gas and diesel) not just for the environment but other drivers....think of the poor soul behind you....I get behind a car running without a cat that is not running perfectly and usually can smell it 5-6 cars length ahead....
A diesel car that's running a bit rich (ever stand next to a rig doing a Regen with side pipes ?) will make a pretty bad stench? Hint, it will make you sick from the stench, kinda like you mentioned.

 

[Porch]

Aww....now you understand why emissions systems created a QOL improvement (both gas and diesel) not just for the environment but other drivers....think of the poor soul behind you....I get behind a car running without a cat that is not running perfectly and usually can smell it 5-6 cars length ahead....
A diesel car that's running a bit rich (ever stand next to a rig doing a Regen with side pipes ?) will make a pretty bad stench? Hint, it will make you sick from the stench, kinda like you mentioned.

So, how much, if any, better is it for the environment, for a dpf to collect the soot then burn it off? Whenever my car was doing a regen, it smelled just as bad as a straight pipe. Fwiw, the high flow cat does make a big difference compared to no cat. But I would still love for it to smell less.