Catless downpipe smell

[Mandinca]

I have the VRSF catless downpipes and the MHD 2 tune. When I put them on I immediately noticed the smell. It didn't bother me at first but over the years it has really started to and now I am at the point where I don't look forward to getting in it anymore. It's an E88 so with summer coming I want to drive it.

The smell is terrible on startup but not as noticeable afterwards.
I still have secondary cats. (no other exhaust mods)
It is very noticeable in the cabin with the windows closed and roof up.
It is not as noticeable from behind the car.

What do people think ?
Does anyone else have these exact symptoms and if so were you able to fix it ?

I read a lot of differing opinions of hi flow cats, some for, some against.
With this being so noticeable inside and at startup - would they even help ?

The only other thing I can think of is that the turbo to DP gaskets are shot. (where the V band holds it together)

Anything else that anyone can think of would be much appreciated.

I tried posting this yesterday but don't see it so apologies if it's here twice. I know there are some posts about this but most are over 5 years old now so I
am trying to find out any new information if possible.

Thanks.

[darkrom]

The reality here is you're going to need to compare to another FULLY catless car. You still have secondaries, I would think this would be pretty mild. It's the problem of how subjective this is. If your car stinks more than another N54 that is catless you might have a leak. If they smell about the same to you and the difference is you have a vert, then nothing you can do besides add a high flow cat.

I will say that this is extremely hard to narrow down without a similar car to compare to. You can try replacing the gaskets but it's a huge pain in the ass, so first I would try to find a local whos car you can sniff and possibly save yourself some headache.

I don't find my fully catless (no secondaries) 135 to stink much on the scale of things, but my B58 stinks like high hell to the point where I assume there must be a leak I need to track down. Good luck, but like I said find a car to compare and save yourself a lot of headache since the downpipes are not an easy thing to remove to replace the gasket just in case.

[drover135]

Yeah, you’re either going to have to go through the hassle of replacing your gaskets (cheap) which might potentially be a waste of time, or go high flow catted (expensive). Obviously if you’re going to change the turbo to DP gaskets you should change the DP to mid pipe gaskets too, as they tend to leak more frequently (these you could actually change somewhat easily). FWIW I have both DP’s for my N55 and have switched them out several times trying to find the sound I want and even with it straight piped post DP the VRSF high flow catted doesn’t smell at all

[Mandinca]

Thanks.

I was looking at my current DPs and while I believed them to be catless VRSF they are actually the catted ones when I compare them to images I found online.
So my thought is to replace the vband fire seals as well as the mid pipe gaskets and go from there.

I know it's a pain in the ass....I put them on !
I do have Quik Jacks now though so it will be considerably less hassle.

I'll post up when I get around to putting them on.
Unfortunately I don't know of any locals that have an N54. Maybe if someone in central CT sees this, I am in Wolcott.

[Eyeman]

Yep, I switched to catless DPs decades ago and still have the secondary cats. No smell in the cabin even with windows down and not moving unless at a drive thru and the wind blows smell back at me. I'd bet you have a leak.