[allblackcoupe]

Is there a high flow catted downpipe that doesnt cause CEL? n55 engine btw

[wdeerfield]

Fabspeed. But you gotta pay to play. A tune will hide the cel with a catless.

[borboa]

AFE downpipe

[1QuikWS6]

Only catted DP that is guaranteed to not throw CEL is the FabSpeed with Hi Flow 200 Cell HJS Cat Elements as previously mentioned

Proven fact in my case as that is what I use in PA - passes Emissions Inspection every time, no CEL

FabSpeed is actually based in PA so I made sure when I ordered they were certain. Tech stated they had many cars in PA using them without a problem & if my car didn't pass they would accept return for full refund

Any other DP mfg. NOT using the HJS Cat Elements, that state they will not throw CEL, are full o poop

And yes, they are expensive ~$1400 - should have bought one during Cyber Monday sale when they were 25% off

They are truly a work of art & fitment is dead on

[Bmwman325]

Love my Fabspeed, 5000 plus miles, no CELS

[alohasurftoad]

saw this in the classifieds. seems worth it to inquire about.

https://f30.bimmerpost.com/forums/sh....php?t=1540794

[Bradshaw88]

Originally Posted by allblackcoupe

Is there a high flow catted downpipe that doesnt cause CEL? n55 engine btw

I have 20,000 miles and no CEL on my Fabspeed HFC.

[IK6SPEED]

No issues with CG Precision.

Essentially same as Fabspeed with HiFlow 200 Cell Cat except its available with a larger custom output connection that increases flow to their exhaust system, which can be seen in figures 3-5 below.

I have larger output diameter (3.5” instead of OEM 3.0”) from output all the way out the rear end.

And the CG Precision are cheaper the Fabspeed.

That said, Fabspeed is still a great solution, but there is a better one.

[FastF30]

Originally Posted by IK6SPEED

No issues with CG Precision.

Essentially same as Fabspeed with HiFlow 200 Cell Cat except its available with a larger custom output connection that increases flow to their exhaust system, which can be seen in figures 3-5 below.

I have larger output diameter (3.5” instead of OEM 3.0”) from output all the way out the rear end.

And the CG Precision are cheaper the Fabspeed.

That said, Fabspeed is still a great solution, but there is a better one.

I would of bought it but they have been out of stock for a longgggg time... went with fabspeed ...

[IK6SPEED]

Originally Posted by FastF30

I would of bought it but they have been out of stock for a longgggg time... went with fabspeed ...

They are hard to obtain. Agreed.

Most all their work on exhausts now is custom.

[Jeff@TopGearSolutions]

Fabspeed is a good one I've also heard success stories with VRSF High Flow Catted and Wagner too.

[FastF30]

Originally Posted by Jeff@TopGearSolutions

Fabspeed is a good one I've also heard success stories with VRSF High Flow Catted and Wagner too.

If you consider a day or two without a cel a success then yes... But me being the way I am ... I would of never of bought the fabspeed if there was another inexpensive option... and there has been zero reports on a EWG passing with one of those... fabspeed has enough reports to state the claim...

So in the end as they say you get what you pay for... I'm an Engineer and I only buy what works not based on price... with that said... everything I end up buying is expensive.... lol......

[BulsaraF36]

+1 for Fabspeed.

I have it installed since April along with Dinan stg4 + big turbo without any CEL. It also makes the MPE sound so much better.

[TEST DRYVER]

I purchased an AR design catted downpipe (200 cell), that was advertised to not throw a check engine light. I don't believe it's guaranteed, but it is advertised. I had some problems with my car recently, so I applied the stock tune on my BM3 for about 200 miles before taking it to the dealership. Check engine light came on after about 50 miles of driving on the stock tune. It could be a check engine because of the problem I'm having, but I'll know soon enough. The problem was fixed at the Dealership (under warranty). I'm sure they probably turned the CEL off before giving it back (my wife picked up the car from the dealership today, so I've yet to see it). I will drive about 50 miles on the stock tune to see if the CEL goes back on, before downloading the tune. If the CEL turns back on after 50 miles, it's likely that the hi-flo downpipe is setting off the CEL. I'll report back...

[TEST DRYVER]

Question: You have 2 little holes in different spots on a downpipe, 1 gets attached to a sensor (I believe an O2 sensor), but what's the other one for? Do we plug it? If we do plug it, what type of material do we use to plug it? I'm sure this is an easy question for many of you, but my car has been running rough, and I'm trying to narrow down the problem. I found 1 of the 2 holes completely open. Is it supposed to stay open? Stupid question, I know. But please advise...

[1QuikWS6]

Originally Posted by TEST DRYVER

Question: You have 2 little holes in different spots on a downpipe, 1 gets attached to a sensor (I believe an O2 sensor), but what's the other one for? Do we plug it? If we do plug it, what type of material do we use to plug it? I'm sure this is an easy question for many of you, but my car has been running rough, and I'm trying to narrow down the problem. I found 1 of the 2 holes completely open. Is it supposed to stay open? Stupid question, I know. But please advise...

If you look at the FabSpeed DP pics I posted in #4 you see (2) bungs

(1) is BEFORE the cat element and is used for the upstream O2 sensor (regulating lambda probe) that is used for engine management/control

(1) is AFTER the cat element and is used for the downstream O2 sensor (lambda monitor sensor) that monitors functionality of the cat

I'm guessing that this DP was not installed by you? If you have (1) of those bungs open, with NO O2 sensor installed (I'm guessing the one missing is downstream O2 since car would not run without the upstream O2 installed) that would definitely affect how the car is running & should be causing a CEL constantly

[VAF30]

5K miles on my Fabspeed with no CEL and custom tune on MHD platform.. Had a small fitment issue in that the flange had to be machined down a bit to ensure a good fit to the turbo,, but a minor nuisance handled by the installer.. all in all happy with the results

[FastF30]

Originally Posted by VAF30

5K miles on my Fabspeed with no CEL and custom tune on MHD platform.. Had a small fitment issue in that the flange had to be machined down a bit to ensure a good fit to the turbo,, but a minor nuisance handled by the installer.. all in all happy with the results

What? don't say this... great... I'll let the installer know... did it look like a one time deal or possible just that's the way it is... first I've heard of fitment issue... How long ago did you install this... hoping I have a newer better batch...

[TEST DRYVER]

Originally Posted by 1QuikWS6

If you look at the FabSpeed DP pics I posted in #4 you see (2) bungs

(1) is BEFORE the cat element and is used for the upstream O2 sensor (regulating lambda probe) that is used for engine management/control

(1) is AFTER the cat element and is used for the downstream O2 sensor (lambda monitor sensor) that monitors functionality of the cat

I'm guessing that this DP was not installed by you? If you have (1) of those bungs open, with NO O2 sensor installed (I'm guessing the one missing is downstream O2 since car would not run without the upstream O2 installed) that would definitely affect how the car is running & should be causing a CEL constantly

Ok, this information is greatly appreciated! So I can't personally install shït! I've been involved in performance cars and modifications for several years, on many different brands and platforms. I read quite a bit and understand the differences in parts and how or why the work (kind of =). But I don't install a single item. I leave that to professionals. I make my money doing what I know best, and I pay people to do what they know best. My wife makes fun of me because I can't fix basic things around the house, but I do always get it fixed...
As far as the downpipe; I have a 2015 335i M-sport with an AR design catted downpipe. After some recent trouble with the car, I had a non tuner mechanic (Porsche Master Tech) take a peek under the hood to see if there's anything out of place. I was actually the one to notice that nothing was connected to the lower bung. The tech inspected the downpipe and saw that the bung was completely uncovered and was open all the way through. This tech is a smart guy, but he does not work on modified cars. When he saw the open bung, he capped it off with something (I'm not sure what). He said having that open could trigger a CEL and possibly effect the cars performance. So was that wrong? Should I not be covering the hole? Is there something that fell out that needs to be reconnected?
Please advise...

The car was at the Dealership for a day, then my wife has been driving the Beemer for the last 2 days, so I've yet to drive it. I'm still on a stock tune and the car has yet to set off a CEL. My drive to work is 50 miles. I'll drive it to work tomorrow, and if I don't have a CEL light by the time I get to work, I'll re-install the BM3 tune.

[louielouie]

Originally Posted by TEST DRYVER

Ok, this information is greatly appreciated! So I can't personally install shït! I've been involved in performance cars and modifications for several years, on many different brands and platforms. I read quite a bit and understand the differences in parts and how or why the work (kind of =). But I don't install a single item. I leave that to professionals. I make my money doing what I know best, and I pay people to do what they know best. My wife makes fun of me because I can't fix basic things around the house, but I do always get it fixed...
As far as the downpipe; I have a 2015 335i M-sport with an AR design catted downpipe. After some recent trouble with the car, I had a non tuner mechanic (Porsche Master Tech) take a peek under the hood to see if there's anything out of place. I was actually the one to notice that nothing was connected to the lower bung. The tech inspected the downpipe and saw that the bung was completely uncovered and was open all the way through. This tech is a smart guy, but he does not work on modified cars. When he saw the open bung, he capped it off with something (I'm not sure what). He said having that open could trigger a CEL and possibly effect the cars performance. So was that wrong? Should I not be covering the hole? Is there something that fell out that needs to be reconnected?
Please advise...

The car was at the Dealership for a day, then my wife has been driving the Beemer for the last 2 days, so I've yet to drive it. I'm still on a stock tune and the car has yet to set off a CEL. My drive to work is 50 miles. I'll drive it to work tomorrow, and if I don't have a CEL light by the time I get to work, I'll re-install the BM3 tune.

Confirming yes, both should have different O2 sensors connected per 1QuikWS6's post.

Also +1 for Fabspeed. Almost a year with no issues.

[F30NFifty5]

Originally Posted by allblackcoupe

Is there a high flow catted downpipe that doesnt cause CEL? n55 engine btw

Just installed my VRSF catted downpipe Friday. No CEL as of yet

[Logicoeur]

Originally Posted by F30NFifty5

Just installed my VRSF catted downpipe Friday. No CEL as of yet

Tuned or no?