[AndyW]

Everytime I start thinking about getting catless downpipes, some person driving a 1960's era car drives by, I get a whiff, and go "no way!"....sigh. Looks like the Cobb high flow catted DP's are in my future...anyone got any experience with them?

[dbworld4k]

Coupes and convertibles have secondary cats and do not smell.

[RSL]

Originally Posted by AndyW

Everytime I start thinking about getting catless downpipes, some person driving a 1960's era car drives by, I get a whiff, and go "no way!"....sigh. Looks like the Cobb high flow catted DP's are in my future...anyone got any experience with them?

Fit great, sound great (335IS with exhaust flap open). Cold start is noticeably louder than stock. With the flap open, it's about perfect for my taste on the stock IS exhaust. I purposely went catted so the exhaust sound/volume wouldn't change much. With the flap closed, almost stock volume at idle/cruise (quiet) and plenty loud at WOT when flap opens. No drone at cruise with the flap open, but you definitely hear it more.

On my original IKC0S_IS rom, they triggered cat code within an hour of driving, which I promptly disabled in my tune and forgot about. Not sure if that was in any way related to them "breaking in". I am not particularly aware of any such thing, but they did have that new cat smell for a couple of heat cycles and DME/O2s are really sensitive, so who knows. Since updating to INA0S_IS rom though, I re-enabled cat codes just to see. Catalyst system went in ready state months ago and haven't had any cat codes at all

[jwebb335xi]

Originally Posted by AndyW

Everytime I start thinking about getting catless downpipes, some person driving a 1960's era car drives by, I get a whiff, and go "no way!"....sigh. Looks like the Cobb high flow catted DP's are in my future...anyone got any experience with them?

Check out CP-E as well. I have a set on my 08 335xi. The fit was perfect. Lifetime warranty. They sound a bit louder than stock and definitely brought more power to the table.

What kind of cats are used on the Cobb units? I take it they are made of a metallic substrate as well?

[AndyW]

Originally Posted by dbworld4k

Coupes and convertibles have secondary cats and do not smell.

Really? I knew about the secondary cats but didn't think they prevented all the smell on their own.

[AndyW]

Originally Posted by RSL

Fit great, sound great /cobb_dps2.jpg[/img]

Thx for the detailed info! Especially on volume, because that is another concern for me. I like that BMW's provide "elegant" power...I actually like the tone and volume of the stock system (I also have the golf tee mod) and don't want a really LOUD exhaust.

[AndyW]

Originally Posted by jwebb335xi

Check out CP-E as well. I have a set on my 08 335xi. The fit was perfect. Lifetime warranty. They sound a bit louder than stock and definitely brought more power to the table.

Thx, I will!

[mike@x-ph.com]

Cobb catted downpipes fit very well. As mentioned above CPE is a really good option as well.
The smell with catless downpipes is overrated. You will only smell it if on cold start and you leave the car idle for couple minutes.

[AndyW]

Originally Posted by mike@x-ph.com

Cobb catted downpipes fit very well. As mentioned above CPE is a really good option as well.
The smell with catless downpipes is overrated. You will only smell it if on cold start and you leave the car idle for couple minutes.

THx. I have heard people downplay the smell...but I am too chicken to try it...I'm cool with the compromise with the catted models.

[mike@x-ph.com]

Originally Posted by AndyW

THx. I have heard people downplay the smell...but I am too chicken to try it...I'm cool with the compromise with the catted models.

Catless DP are not for everyone, good luck with the catted option and let me know if you need any help

[david in germany]

Following this. I also do not like the idea of catless as where i live they are required to drive in certain areas.

[RSL]

Originally Posted by RSL

On my original IKC0S_IS rom, they triggered cat code within an hour of driving, which I promptly disabled in my tune and forgot about. Not sure if that was in any way related to them "breaking in". I am not particularly aware of any such thing, but they did have that new cat smell for a couple of heat cycles and DME/O2s are really sensitive, so who knows. Since updating to INA0S_IS rom though, I re-enabled cat codes just to see. Catalyst system went in ready state months ago and haven't had any cat codes at all

I wanted to follow up on this regarding different roms triggering or not triggering cat efficiency codes on high-flow catted DPs. As I mentioned before, I got codes on IKC0S_IS within about an hour of driving on Cobb catted DPs, but have not had a single code in months of driving on INA0S. I wasn't able to say if the different roms had anything to do with it, but I am now able to say that with some certainty. I flashed to IJE0S_IS today and the cat codes lit up literally within 5 miles. Seems like good empirical evidence that the newer the rom, the more tolerant it is and INA0S has apparently crossed a threshold that makes it a complete non-issue (for me at least).

I'm not sure if ILA0S (between IKC0S and INA0S) has the more or less tolerant behavior, but if you have catted DPs and are running or can flash to INA0S, there certainly seems to be a very high probability of running high-flow cats with codes enabled (ie. all MIL systems ready) and not throw codes...

IJE0S = triggered around 5 miles
IKC0S = triggered around 40 miles
INA0S = thousands of miles with absolutely no codes

[JasW]

Originally Posted by AndyW

THx. I have heard people downplay the smell...but I am too chicken to try it...I'm cool with the compromise with the catted models.

I know this is from a couple of months ago, but any smell with catless DPs is absolutely negligible. I deleted my secondary cats not long after installing catless DPs, and that's where the smell really kicks in. It's not only like re-living the 60s, it's like driving in the Holland Tunnel in the 60s with the windows rolled down.

[Jeff@TopGearSolutions]

Originally Posted by JasW

I know this is from a couple of months ago, but any smell with catless DPs is absolutely negligible. I deleted my secondary cats not long after installing catless DPs, and that's where the smell really kicks in. It's not only like re-living the 60s, it's like driving in the Holland Tunnel in the 60s with the windows rolled down.

The 60's?!

Most guys here don't even know what the 80's were LOL

You are right though, catless with stock secondaries wasn't bad. On my previous car I was full catless and it reeked.

Originally Posted by RSL

I wanted to follow up on this regarding different roms triggering or not triggering cat efficiency codes on high-flow catted DPs. As I mentioned before, I got codes on IKC0S_IS within about an hour of driving on Cobb catted DPs, but have not had a single code in months of driving on INA0S. I wasn't able to say if the different roms had anything to do with it, but I am now able to say that with some certainty. I flashed to IJE0S_IS today and the cat codes lit up literally within 5 miles. Seems like good empirical evidence that the newer the rom, the more tolerant it is and INA0S has apparently crossed a threshold that makes it a complete non-issue (for me at least).

I'm not sure if ILA0S (between IKC0S and INA0S) has the more or less tolerant behavior, but if you have catted DPs and are running or can flash to INA0S, there certainly seems to be a very high probability of running high-flow cats with codes enabled (ie. all MIL systems ready) and not throw codes...

IJE0S = triggered around 5 miles
IKC0S = triggered around 40 miles
INA0S = thousands of miles with absolutely no codes

Thanks for sharing that info! Very interesting indeed

Newb question of the day though: how do you actually change roms? I did a search on this and other forums to research the process but couldn't really find the steps involved, or limitations, etc. Thanks!

[RSL]

Originally Posted by FCobra94

Thanks for sharing that info! Very interesting indeed

Newb question of the day though: how do you actually change roms? I did a search on this and other forums to research the process but couldn't really find the steps involved, or limitations, etc. Thanks!

MHD is probably easiest, then WinKFP. You'd need a d-can cable either way, but with MHD, theres no separate software to install/setup. When attempting to flash back to stock with no rom file present, MHD will build the latest rom for your DME. Make a back up of your original rom beforehand in case you ever want to go back to it though. If you want to try older roms, you'd need a copy of the rom file and then flash "back to stock" using them as the file. If you use WinKFP, you'd need to know the ZSB number (BMW part number) of the rom you want to flash and it will build it based on that.

If you're on IA80S though, I don't think there's anything newer you can use because it's a different DME. Just make sure any rom you're flashing manually is for the same DME and car type (ie. I wouldn't try flashing a 1M bin to a 335

[BSM n54iS]

Originally Posted by RSL

I'm not sure if ILA0S (between IKC0S and INA0S) has the more or less tolerant behavior, but if you have catted DPs and are running or can flash to INA0S, there certainly seems to be a very high probability of running high-flow cats with codes enabled (ie. all MIL systems ready) and not throw codes...

RSL helped me to decide and go w/ the Cobb dp also, put them on over a week ago now..100+ miles. I'm on the ILAOS IS rom and no codes thrown whatsoever

[RSL]

Saw the review, glad you like them Thanks for the info on ILA0S too!

[jwebb335xi]

Originally Posted by mike@x-ph.com

Cobb catted downpipes fit very well. As mentioned above CPE is a really good option as well.
The smell with catless downpipes is overrated. You will only smell it if on cold start and you leave the car idle for couple minutes.

I have CPE catted DPs. I have not noticed any exhaust smell since install. The car sounds better and has more power. It will hit a load of 195-197; and, was hitting just over 180 before the DPs.

[JasW]

I just ordered them for my 335is, too, to replace my AR catless. The 335is and catless DPs don't mix, not unless you're a big Honda Civic rasp and drone fan. Unlike the regular 335i, resonators won't cure the problem. I'm more than glad to lose the 5hp edge catless DPs have over catted to get rid of that nasty sound. When you're FBO, have an upgraded LPFP and are running E60, who cares if you get 445whp instead of 450whp (or whatever).

[Mike@N54Tuning.com]

Originally Posted by proTUNING Freaks

High flow catted downpipes are really great performers especially on stock turbo applications including those running higher boost and octane such as meth/E85 blends/race gas. We haven't seen any significant power loss from going with the high flow catted downpipes vs. decat. Any dyno number differences are within dyno margins of error and can be ignored. Cobb makes a really great quality set. You can't go wrong there.

From our experience like you said the high flow catted are great pipes but they loose about half the gains from fully catless. So if you gain 30 from catless you will gain about 15-20 from catted.

Mike