[m4thijss]

Maybe current catless owners can give some insight. I have a few questions

1. How bad is the smell, more so would my mother hate me when I go home and start my car in the garage?
2. I've heard that some sort of exhaust can discolor the rear bumper when going catless is that a thing?
3. I am planning on tuning my car with boot mod3 will it pass emissions in Northern Virginia? I've done some reading and supposedly yes but I'd like to hear from someone who's actually done it.
4. Is the sound difference noticeable?

Finally, do you think it's worth going catless or keep the stock cat or doing a high-flow cat? Thanks for the help!

[thejeremyman9]

1. This is subjective, but it is terrible. I've driven a catless 3000gt for many many years. Everyone kept telling me the F3x wouldnt be as bad (modern car, better combustion, etc), but i sold my IC to someone who was catless and the second they started their car it was extremely noticeable and was just as bad. One of the reasons i went catted...

2. You are going to get a lot more carbon (black spots, etc) on your back bumper when catless. It is going to accumulate rather quickly.

3. Depends how many monitors you can have not ready.

4. Yes, very. Even with stock exhaust it is, and the difference is even bigger with aftermarket exhausts. Catless can drone if you already have an aftermarket exhaust.

Get a HFC, you arent really sacrificing anything for a stock turbo application and you avoid all the negatives of catless.

[BMWILUVU]

Some people like the smell and will get high on anything but most will think it smells god-awful and at traffic stops the smell sometimes enters the cabin. I don't get discoloration but if you are concerned just make sure your exhaust tips clear the bumper. You are not going to pass emissions with a catless. I have tried and it is less effort to put the stock cat back on for inspection. The sound on cold-start will have everyone up in the morning.

[m4thijss]

Originally Posted by thejeremyman9

1. This is subjective, but it is terrible. I've driven a catless 3000gt for many many years. Everyone kept telling me the F3x wouldnt be as bad (modern car, better combustion, etc), but i sold my IC to someone who was catless and the second they started their car it was extremely noticeable and was just as bad. One of the reasons i went catted...

2. You are going to get a lot more carbon (black spots, etc) on your back bumper when catless. It is going to accumulate rather quickly.

3. Depends how many monitors you can have not ready.

4. Yes, very. Even with stock exhaust it is, and the difference is even bigger with aftermarket exhausts. Catless can drone if you already have an aftermarket exhaust.

Get a HFC, you arent really sacrificing anything for a stock turbo application and you avoid all the negatives of catless.

I was originally looking at a high flow but the thing that really made me think to go catless is the price and potentially going catless in the future. Especially since I plan to go stage 2 once I get better cooling and possibly f80/82 brakes.

[thejeremyman9]

Originally Posted by m4thijss

I was originally looking at a high flow but the thing that really made me think to go catless is the price and potentially going catless in the future. Especially since I plan to go stage 2 once I get better cooling and possibly f80/82 brakes.

You dont need catless to go stage 2... There's really no reason to go catless with stock turbo except for the price difference, and you can get cheaper catted options for only ~150$ more than catless, so even that is negligible. Some could argue catless sounds better, but that's also subjective, and there are other ways to achieve sound changes.

[m4thijss]

Originally Posted by thejeremyman9

You dont need catless to go stage 2... There's really no reason to go catless with stock turbo except for the price difference, and you can get cheaper catted options for only ~150$ more than catless, so even that is negligible. Some could argue catless sounds better, but that's also subjective, and there are other ways to achieve sound changes.

I was planning on going VRSF but do you have any other recomendations?

[n55david]

everything I own is catless, other than my attitude towards emissions and the environment... what does that tell you?

[thejeremyman9]

Originally Posted by m4thijss

I was planning on going VRSF but do you have any other recomendations?

Depends on what you need with respect to emissions... VRSF and CTS are the cheapest catted options, then there are mid-tier ones (probably not worth it), then the most expensive ones like AA and fabspeed. AA is technically the only one that is EPA certified for emissions (should be 49 state legal, but confirm). All except fabspeed, AA, and CG will throw a CEL and not pass emissions.

[Pussiwillow]

Catless only sucks if you leave your car running while wrestling something in the trunk for like longer than 10 seconds. Or if you leave it running in the garage for a little bit, I always fire it up and move it out, wife drives the car often and never complains, ya you'll smell it, you'll smell it at traffic lights if windows are down, it is what it is, I have zero regerts

[voxumf30]

Originally Posted by m4thijss

Maybe current catless owners can give some insight. I have a few questions

1. How bad is the smell, more so would my mother hate me when I go home and start my car in the garage?
2. I've heard that some sort of exhaust can discolor the rear bumper when going catless is that a thing?
3. I am planning on tuning my car with boot mod3 will it pass emissions in Northern Virginia? I've done some reading and supposedly yes but I'd like to hear from someone who's actually done it.
4. Is the sound difference noticeable?

Finally, do you think it's worth going catless or keep the stock cat or doing a high-flow cat? Thanks for the help!

I recently got my VRSF catless(ceratoke coated) DP installed and here are my thoughts.

1. Smell can be bad under certain situations, for example sitting in a drive through line with windows down, you will leave your car smelling like gas. Which I love, but can linger for a little while.

2. I have no discoloration with stock exhaust.

3. I have no emissions in my state, so no comment here.

4. Sound is totally subjective, but I absolutely love it. It's deeper, and all of the natural burbles are much more pronounced. The upshifts on heavy throttle give you more of that brrrrp sound, (sounds like a DSG / DCT). You will also be able to hear the turbo spool as opposed to just the diverter.

The biggest benefit I found was the performance. I immediately went stage 2+ (MHD) after install and it feels like there is little to no turbo lag now, and it drives much smoother compared to stock downpipe with stage 1.

[drapzzy]

Its quite funny reading all these and its probably different since I have secondary cats, but I would say I only smell it if I start it in the garage or if its cold in general, after its heated I really have to try to smell it to smell it if you know what I mean. At stop lights sure and my friend recently told me that If he drives behind me he has to roll his windows up so take this info as you please, but its worth it in my opinion!

[n55david]

Originally Posted by drapzzy

Its quite funny reading all these and its probably different since I have secondary cats, but I would say I only smell it if I start it in the garage or if its cold in general, after its heated I really have to try to smell it to smell it if you know what I mean. At stop lights sure and my friend recently told me that If he drives behind me he has to roll his windows up so take this info as you please, but its worth it in my opinion!

yeah, you dont count. not the same setup.

[drapzzy]

Originally Posted by Phantom10R

yeah, you dont count. not the same setup.

always left out haahaha

[thejeremyman9]

Originally Posted by drapzzy

Its quite funny reading all these and its probably different since I have secondary cats, but I would say I only smell it if I start it in the garage or if its cold in general, after its heated I really have to try to smell it to smell it if you know what I mean. At stop lights sure and my friend recently told me that If he drives behind me he has to roll his windows up so take this info as you please, but its worth it in my opinion!

Totally different... you still have cats. Your situation is basically the same as running a catted DP, since the catted DPs basically removed half of the cats (OEM has two separate catalyst "packs"). Of course the aftermarket cats are also not of OEM construction, so that has an impact as well. But yeah, no comparison to catless.

The bottom line is catless is cheaper and louder, but it undeniably produces significant fumes (the tolerance for which is subjective) and can pose emissions compliance issues.

Catted mitigates negative effects, is slightly to much more expensive, may or may not pass emissions, and offers nearly all the benefit of going catless, at least for stock turbo application.

[johnung]

Originally Posted by m4thijss

Maybe current catless owners can give some insight. I have a few questions

1. How bad is the smell, more so would my mother hate me when I go home and start my car in the garage?
2. I've heard that some sort of exhaust can discolor the rear bumper when going catless is that a thing?
3. I am planning on tuning my car with boot mod3 will it pass emissions in Northern Virginia? I've done some reading and supposedly yes but I'd like to hear from someone who's actually done it.
4. Is the sound difference noticeable?

Finally, do you think it's worth going catless or keep the stock cat or doing a high-flow cat? Thanks for the help!

Emissions requirements are different in every state. There are already many great comments on this thread. The most common misunderstanding that people make has to do with Check Engine Lights on the dashboard.

A catless downpipe can cause a CEL on the dashboard. Tunes like Bootmod3 and MHD can suppress the CEL so it doesn't appear. But that does not mean that the tune will help to pass state emissions. If a state (like NJ) plugs into the OBD port under the dash then the error will be visible and the car will fail emissions.

I got a Fabspeed HJS catted downpipe three years ago. Catalytic converters are not commodity products. The quality various widely depending on the manufacturer. HJS European made cats are known as the best. The Fabspeed passed right through NJ emissions with a BM3 Stage2 tune.

Hope this helps!

[mcsweeto]

Originally Posted by thejeremyman9

1. This is subjective, but it is terrible. I've driven a catless 3000gt for many many years. Everyone kept telling me the F3x wouldnt be as bad (modern car, better combustion, etc), but i sold my IC to someone who was catless and the second they started their car it was extremely noticeable and was just as bad. One of the reasons i went catted...

2. You are going to get a lot more carbon (black spots, etc) on your back bumper when catless. It is going to accumulate rather quickly.

3. Depends how many monitors you can have not ready.

4. Yes, very. Even with stock exhaust it is, and the difference is even bigger with aftermarket exhausts. Catless can drone if you already have an aftermarket exhaust.

Get a HFC, you arent really sacrificing anything for a stock turbo application and you avoid all the negatives of catless.

Listen to this man. Not that he needs it, but to back him up...

1. It smells, and is noxious. Anyone who says otherwise either has a current COVID infection or was born without olfactory glands. It's not like a fart, you can't pretend it away.

2. Too long between washes and you'll be elbow greasing discoloration off the finish.

3. I invoke my 5th Amendment rights.

4. Yes, definitely raspier. And God forbid don't delete your resonator too.

If you really want to go catless, my 4" VRSF one will be off my '15 F32 in a couple weeks.

[Info@mad-us.com]

We can help! Give our site a click below.

[m4thijss]

Originally Posted by mcsweeto

Listen to this man. Not that he needs it, but to back him up...

1. It smells, and is noxious. Anyone who says otherwise either has a current COVID infection or was born without olfactory glands. It's not like a fart, you can't pretend it away.

2. Too long between washes and you'll be elbow greasing discoloration off the finish.

3. I invoke my 5th Amendment rights.

4. Yes, definitely raspier. And God forbid don't delete your resonator too.

If you really want to go catless, my 4" VRSF one will be off my '15 F32 in a couple weeks.

How much would you want for the cat and where are you located?

[mcsweeto]

Originally Posted by m4thijss

How much would you want for the cat and where are you located?

West/central NC. I got it off yesterday. What are they selling for now? VRSF 4" catless, n55. The gasket and top vband clamp are in good shape, I lost the midpipe clamp somewhere cleaning up after myself.

DM me an offer.

[jew82]

Recently went catless in Mexico too. Smell is pretty damn strong and I may need to go back catted. Way worse than my catless STI.

It drives better and spools better I think from the butt dyno. Feels like its just breathing better and more effortlessly.

[boosted14]

I have had a VRSF catless dp on my 2014 435i as well as AWE midpipe and axle back exhaust and i have never smelled anything bad. Maybe you guys need to change your cabin filters! lol

[mcsweeto]

Originally Posted by boosted14

I have had a VRSF catless dp on my 2014 435i as well as AWE midpipe and axle back exhaust and i have never smelled anything bad. Maybe you guys need to change your cabin filters! lol

Originally Posted by mcsweeto

...

1. It smells, and is noxious. Anyone who says otherwise either has a current COVID infection or was born without olfactory glands. It's not like a fart, you can't pretend it away.
...

I stand by my earlier comment.