[matamua]

I've got an e93 and I'm looking to upgrade DPs so I can move to stage 2/2+. For those who have made this move and otherwise kept stock exhaust, how big of a difference in smell and volume did you notice?

I've heard people say catless DPs smell and others say that they don't because of the secondary cats.

I've also heard they are louder than either catted DPs or stock DPs, and others say there is no real difference.

What say you?

[ragingpanda]

If you are going to keep your stock exhaust with the secondary kitties, the sound is going to sound deeper (very nice!). It is going to be a tiny bit louder but it is not offensive at all (no rasp or drone) as long as you have your secondary kitties.

If you have your windows down and you are stationary, you will most likely be able to smell it (I know I did, but I don't mind it).

[IllSic_Design]

I have secondary cats still and don't think I've ever noticed the smell, and my noise is usually pretty sensitive to odd smells. I drive with my windows down 95% of the time

[sbsk518]

I have an e93 and 95% of the time I dont even notice the smell, even sitting on traffic with the top down. Just install the DPs. It's well worth the performance gain.

The sound is way better with DPs also.

[flyin54]

Id say 20% more louder

[Bimmer_Bro]

Sound and performance is awesome. I have the corsa exhaust.
I 100% notice the smell. Smells like an old Honda now. You won't notice it when you are driving. I notice it going in reverse with the windows down, stationary with the windows down, or if I do some downshifts before stopping at a traffic light, I will get a huge whiff once I stop. Again this is only with the windows open. If you had everything closed you would not smell it.

[E92.Dom]

N55 here, when I went catless the sound, intoxicating. It sounds incredible. Quiet in low rpms pure bliss when you want it. Smell... well it smells like a catless car, I enjoy the smell but N55 also doesn't have secondary cats. Windows up I can't smell it only when stopped with the windows open. Enjoy!

[fgpalmer71]

I also have an E93 and installed the DP's a couple of months ago. Yes.....they do smell. The only time I notice it is when it's in the garage or the 1 time I was behind it while letting my dad drive it. He took off from a light and I could smell it. I will say the smell has seemed to dissipate over time. When the top is down and I'm stopped at a light I smell nothing though. No worries.

Sound is pretty fantastic with the stock exhaust in my opinion. The added turbo noises, that's my favorite part other then the power stage 2+ provides.

[whyzee125]

On N54, I don't notice the smell, I guess due to the secondary cats. On my N55 it smelled like a go kart track lol.

Sound, IMO, isn't louder but definitely different. I prefer the exhaust note with stock DPs but the turbo whistle is nice. PE mod helped a lot, and it now sounds great with DPs and I would say is 10% louder than stock.

[matamua]

Thanks everybody! Seems the consensus is that drawbacks are minor and upsides are well worth it.

I'll update this once I've got them.

[_N54]

Whatever you do don't run the secondary cats deleted without resonators. The car sounds like shit. Run vibrant resonators. I have my secondaries in place and it masks 90% of the smell except some times you smell a bit of the fumes from the meth injection after a WOT pull.

[Gregrobin]

Originally Posted by fgpalmer71

I also have an E93 and installed the DP's a couple of months ago. Yes.....they do smell. The only time I notice it is when it's in the garage or the 1 time I was behind it while letting my dad drive it. He took off from a light and I could smell it. I will say the smell has seemed to dissipate over time. When the top is down and I'm stopped at a light I smell nothing though. No worries.

Sound is pretty fantastic with the stock exhaust in my opinion. The added turbo noises, that's my favorite part other then the power stage 2+ provides.

Which ones did you install, make and model?

[ky0u]

Originally Posted by 6266N54

Whatever you do don't run the secondary cats deleted without resonators. The car sounds like shit. Run vibrant resonators.

Do this. I'm running catless DP and 2nds replaced with vibrants (+ golf tee mod). Note is perfect to me. Unnoticeable at idle and low throttle aside from a deeper growl. Very noticeable at moderate to heavy throttle or at higher RPMS. No rasp or droning whatsoever

[fgpalmer71]

Originally Posted by Gregrobin

Which ones did you install, make and model?

Went with the ARM Catless downpipes. Caught them on sale for something like $230 I think. Really ended up being more then free when I got rid of my stock dp's.

[Gregrobin]

Originally Posted by fgpalmer71

Went with the ARM Catless downpipes. Caught them on sale for something like $230 I think. Really ended up being more then free when I got rid of my stock dp's.

Thank you, if I remember correctly you have an E93? I thought I read somewhere where the catless down pipes for the E93 were different or needed to be modified.

Did you do the install yourself or pay a shop? I've watched videos online, not sure this is one I want to tackle myself. For one I don't have the special socket to remove the sensor. And two not sure I want to lay on my back in the garage for hours, especially after the challenges I had installing the intercooler.

[mike@x-ph.com]

Originally Posted by fgpalmer71

Went with the ARM Catless downpipes. Caught them on sale for something like $230 I think. Really ended up being more then free when I got rid of my stock dp's.

[sbsk518]

No modification necessary on the E93. Install is the same as e92 (assuming RWD).

You don't need the 7/8 socket to remove the O2 sensors (you can use a wrench), but you can pick one up on Amazon for less than $20. Install on e93 isn't hard. The first time I installed the DPs it took me 6 hours (nearly half spent on one bolt), but now I can do it in under 2. It's not hard once you learn what to do.

[fgpalmer71]

Originally Posted by Gregrobin

Thank you, if I remember correctly you have an E93? I thought I read somewhere where the catless down pipes for the E93 were different or needed to be modified.

Did you do the install yourself or pay a shop? I've watched videos online, not sure this is one I want to tackle myself. For one I don't have the special socket to remove the sensor. And two not sure I want to lay on my back in the garage for hours, especially after the challenges I had installing the intercooler.

Yes, E93 here also.

As stated above....nothing different in terms of install. I believe the AWD cars are different.

I installed them myself and also, as stated above, it took me about 6 hours roughly. That was me going extremely slowly, triple checking everything...and yes...laying on my back. I had shoulder surgery with rehab cut short by covid so my right arm isn't but maybe 75% what it should be and that didn't help. I rented the sensor removal tool from Autozone. Cost me about $20 but I can't see myself using it ever again so I rented instead of purchased. If you tackle it....and I think you should....remember that the passenger side turbo to DP clamp is probably easier to tighten from the topside as opposed to the bottom side. A good hour of install time for me was dedicated to that bloody little clamp. After struggling for an hour I took an alcohol break and noticed I could reach it from the top side. Also....a stubby socket wrench and a magnet were my best friends.

It wasn't a bad install....just time consuming. If you give it a go also remember to COMPLETELY re-tighten the 2 bolts that hold the steering rack in. I removed the passenger side bolt and just loosened the drivers side bolt so I could slide the rack forward enough to gain clearance. Worked like a charm, but I didn't get the bolt on the drivers side totally tightened and putting it back up in the air a week later was crappy. I hate retracing my steps after a self inflicted mess up!

[mapleleaf1773]

I have an e90 (328) xdrive I'm thinking about going catless dp because of a damn cat error I'm getting.

I need to figure what to buy. Sorry not thread jacking, ill start a new thread. Just thinking as i read/type.

[Bimmer_Bro]

Originally Posted by mapleleaf1773

I have an e90 (328) xdrive I'm thinking about going catless dp because of a damn cat error I'm getting.

I need to figure what to buy. Sorry not thread jacking, ill start a new thread. Just thinking as i read/type.

You may want to post this in the non-turbo section for better help.
However, you are getting a code either due to bad 02 sensors, clogged cat, or worn out cat.
Going catless is still going to give you error codes. (Unless tuned with the error code programmed out like MHD does.)

[Gregrobin]

Well I called every local BMW service shop and none of them will do a catless downpipe install, so if I go with this upgrade it looks like I'll have no choice but to do it myself. Bad back, elbow, shoulder and all. Girlfriend's father expects to have the new lift installed soon so I'll wait for that.

[stewbets]

Originally Posted by Gregrobin

Well I called every local BMW service shop and none of them will do a catless downpipe install, so if I go with this upgrade it looks like I'll have no choice but to do it myself. Bad back, elbow, shoulder and all. Girlfriend's father expects to have the new lift installed soon so I'll wait for that.

Sounds like a little physical therapy