Catless DPs gaseous odor cause?

[StatenEye]

Hi Guys,

I'm on a modding run right now. Bought the X5M on 3/12. Velos tune a week later, Megan Racing exhaust a week after that, gloss grills, spacers en route.. Next mod is catless or catted downpipes. so far this forum has really helped me with the good and prompt answers I'm receiving from all the guys here.

I hear a lot about the gaseous odor in the cabin. What is causing this? I understand the cats role in cleaning the exhaust but I'm not understanding why the odor seeps into the cabin. I've had catless pipes on my past two turbo BMWs and have never had this issue. Is there anyway to mitigate the odor getting into the cabin? Wrap the downpipes or apply sealant when installing? Not sure what to think of the odor as this car is used to drive my 2yo son around on the weekend. I've reached out to a couple of guys here and they all said the smell is evident, but not that bad. To me any gaseous odor in the cabin would be bad.

I know a lot of peeps are gonna just say the catless pipes are not for me but I would like to here if you guys allowed your little ones in the car bc I need that throttle response and quick spool that the catless pipes offer. Catless pipes Yay or nay?

[mitch808]

Its not leaking, its often just the exhaust smell typically masked by the catalytic converter that your smelling. You are smelling more of what was already there basically.

Some are more sensitive to it than others, like you I think its blown out of proportion a bit.

[gixxerboy63]

I have the same concerns. Looking forward to more input on this subject.

[gixxerboy63]

UPDATE on my DPs.

When I first installed the DPs, I wasn't sure that I would keep them. The odor was noticeable and the truck seemed a little too loud for my taste. In my mind, it didn't really make any more noticeable power, yet the reduced engine bay heat was the biggest motivator for me to keep them. Then I began to like the new exotic sound my truck was making.... It sounded much more aggressive and "M" like.

Now that Active Autowerke has imporved their stage 2+ tune for cattless downpipes, I have noticed less gaseous odor and an increase in torque over their previous tune.

I think I will keep mine now.