if my cat goes out, would it mean that it's now catlessDP?

ty666 · 05-23-2020, 03:22 AM

I have a fabspeed high flow DP on my N55 witha stage 2 BM3 aggressive, i recently increases the burble tune to the max setting and have been doing a lot of downshifting, pops and bangs, after heavy acceleration and downshifts, i smell a burning smell (not oil) and today i got an engine light. I haven't scanned it yet, but I'm assuming my high flow cat is dying. I don't really care much about it anymore as emissions tests are no longer required where I live.
Question is if my high flow dp goes out, does that mean that it's catless now? is there any disadvantage for having a damaged catted dp other than the check engine light?

VictorF32 · 05-23-2020, 03:48 AM

I have a 435i and have had a VRSF Catless down pipe for 6 months ZERO issues keeping the MHD catted/oem box unchecked and hiding the cel. Don't quote me but maybe the backfiring or burble tune is literally melting the honeycomb (filter) inside the cat? And pieces of the honeycomb or the filter are coming out the back little by little because of increased heat and pressure from the tune? I've seen a video of a 3 series revving and pieces of the cat flying out of the exhaust. Running pump gas or e85 maybe the issue?
Just trying to help, hope your able to diagnose and fix that notorious Check engine light, it is a daily struggle.

ty666 · 05-23-2020, 04:30 AM

Quote:

Originally Posted by VictorF32

I have a 435i and have had a VRSF Catless down pipe for 6 months ZERO issues keeping the MHD catted/oem box unchecked and hiding the cel. Don't quote me but maybe the backfiring or burble tune is literally melting the honeycomb (filter) inside the cat? And pieces of the honeycomb or the filter are coming out the back little by little because of increased heat and pressure from the tune? I've seen a video of a 3 series revving and pieces of the cat flying out of the exhaust. Running pump gas or e85 maybe the issue?
Just trying to help, hope your able to diagnose and fix that notorious Check engine light, it is a daily struggle.

Thanks, but i couldn't watch that video till the end, wtf is that guy doing? I'm sure that car is stolen. lol

Logicoeur · 05-23-2020, 06:20 AM

Check the CEL before hypothesizing it's the cat.

alohasurftoad · 05-23-2020, 12:53 PM

it's possible that the excessive "snap, crackle, pop" from max burble tune damaged your catalyst. fabspeed uses metal catalysts which are stronger but you can kill anything with enough effort. if it is damaged you aren't really catless until the catalyst has been burned out or completely removed. if it is partially there the flow is likely worsened.

if it's partially there you need to remove the rest of it. if it's not damaged i suggest you sell it and get a catless downpipe. it's what you should have done prior to going max burble. you can get decent money for a used fabspeed if the catalyst is good, of course.

here is a thread about a melted catalyst...
https://f30.bimmerpost.com/forums/sh...atalyst+melted

Elvisfan · 05-23-2020, 03:40 PM

Quote:

Originally Posted by ty666

I have a fabspeed high flow DP on my N55 witha stage 2 BM3 aggressive, i recently increases the burble tune to the max setting and have been doing a lot of downshifting, pops and bangs, after heavy acceleration and downshifts, i smell a burning smell (not oil) and today i got an engine light. I haven't scanned it yet, but I'm assuming my high flow cat is dying. I don't really care much about it anymore as emissions tests are no longer required where I live.
Question is if my high flow dp goes out, does that mean that it's catless now? is there any disadvantage for having a damaged catted dp other than the check engine light?

Hello,I have a question. Would someone on this forum kindly explain why so many BMW owners apparently don’t care about the air they breath,but really care about how much noise their car makes? I really don’t understand it. Especially not caring about the air.
Thanks.

eluded · 05-24-2020, 03:18 AM

Quote:

Originally Posted by ty666

Quote:

Originally Posted by VictorF32

I have a 435i and have had a VRSF Catless down pipe for 6 months ZERO issues keeping the MHD catted/oem box unchecked and hiding the cel. Don't quote me but maybe the backfiring or burble tune is literally melting the honeycomb (filter) inside the cat? And pieces of the honeycomb or the filter are coming out the back little by little because of increased heat and pressure from the tune? I've seen a video of a 3 series revving and pieces of the cat flying out of the exhaust. Running pump gas or e85 maybe the issue?
Just trying to help, hope your able to diagnose and fix that notorious Check engine light, it is a daily struggle.

Thanks, but i couldn't watch that video till the end, wtf is that guy doing? I'm sure that car is stolen. lol

Gen13 F36 · 05-24-2020, 12:25 PM

Quote:

Originally Posted by Elvisfan

Hello,I have a question. Would someone on this forum kindly explain why so many BMW owners apparently don’t care about the air they breath,but really care about how much noise their car makes? I really don’t understand it. Especially not caring about the air.
Thanks.

I got stock dp. I care about the planet, I recycle and keep my garbage off the street. Just leave my car out of it if I ever go catless.

05-23-2020, 03:22 AM	#1
ty666 Private First Class 72 Rep 122 Posts Drives: BMW 435xi Join Date: Mar 2016 Location: Ottawa, ON, Canada iTrader: (0)	if my cat goes out, would it mean that it's now catlessDP? I have a fabspeed high flow DP on my N55 witha stage 2 BM3 aggressive, i recently increases the burble tune to the max setting and have been doing a lot of downshifting, pops and bangs, after heavy acceleration and downshifts, i smell a burning smell (not oil) and today i got an engine light. I haven't scanned it yet, but I'm assuming my high flow cat is dying. I don't really care much about it anymore as emissions tests are no longer required where I live. Question is if my high flow dp goes out, does that mean that it's catless now? is there any disadvantage for having a damaged catted dp other than the check engine light? __________________ Dinan Stage2 \| Fabspeed High Flow DP \| Dinan Carbn Air Intake \| Remus Exhaust \| H&R Sport Springs \| 19" Savini Wheels \| Continental ExtremeContact Sport Plus \| Rear Diffusr \| M4 Carbn Mirror Caps \| Smoked Sequential Mirror Signls \| Lip Spoiler \| PREVIOUS VEHICLE: 2013 BMW F30 INSTAGRAM: aphotic_f32
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05-23-2020, 03:48 AM	#2
VictorF32 VictorNM 10 Rep 18 Posts Drives: BMW 2016 435i Msport Join Date: May 2020 Location: San Diego, CA iTrader: (0)	I have a 435i and have had a VRSF Catless down pipe for 6 months ZERO issues keeping the MHD catted/oem box unchecked and hiding the cel. Don't quote me but maybe the backfiring or burble tune is literally melting the honeycomb (filter) inside the cat? And pieces of the honeycomb or the filter are coming out the back little by little because of increased heat and pressure from the tune? I've seen a video of a 3 series revving and pieces of the cat flying out of the exhaust. Running pump gas or e85 maybe the issue? Just trying to help, hope your able to diagnose and fix that notorious Check engine light, it is a daily struggle.
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05-23-2020, 06:20 AM	#4
Logicoeur Lieutenant Colonel 990 Rep 1,934 Posts Drives: F30 335i xDrive Join Date: Feb 2018 Location: Boston iTrader: (0)	Check the CEL before hypothesizing it's the cat. __________________ F30 335iX \| Remus Axleback \| Fabspeed Catted DP \| VRSF Comp IC \| 18X9 ET35 19lb MT1 \| 255/40/18 ECS \| Ohlins RT Millway Street \| Millway Control Arm Bushings \| Turner Endlinks \| TMH 75mm 14x1.5 Studs \| BMW MPerf LSD \| XDelete \| Pipercross Filter \| MHD Stg2 93
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05-23-2020, 12:53 PM	#5
alohasurftoad Brigadier General 3072 Rep 4,315 Posts Drives: 440i gran coupe w/mppsk Join Date: Apr 2015 Location: hawaii iTrader: (0)	it's possible that the excessive "snap, crackle, pop" from max burble tune damaged your catalyst. fabspeed uses metal catalysts which are stronger but you can kill anything with enough effort. if it is damaged you aren't really catless until the catalyst has been burned out or completely removed. if it is partially there the flow is likely worsened. if it's partially there you need to remove the rest of it. if it's not damaged i suggest you sell it and get a catless downpipe. it's what you should have done prior to going max burble. you can get decent money for a used fabspeed if the catalyst is good, of course. here is a thread about a melted catalyst... https://f30.bimmerpost.com/forums/sh...atalyst+melted
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