BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
M2 Technical Topics > S55 Engine / Drivetrain / Exhaust / Bolt-ons / Tuning > OPF Removal: CEL or Limp Mode?

Post Reply
 
Thread Tools Search this Thread
      03-11-2019, 06:39 PM   #45
Karlosm2c
Lieutenant
Karlosm2c's Avatar
United Kingdom
291
Rep
456
Posts

Drives: M2 Competition
Join Date: Oct 2018
Location: Bedfordshire

iTrader: (0)

Quote:
Originally Posted by Bee Pee View Post
Quote:
Originally Posted by Karlosm2c View Post
Quote:
Originally Posted by Bee Pee View Post
Quote:
Originally Posted by "Bee Pee"
DB,

Once OPF limp code is understood/worked around, would it not be cheaper/easier to fit sport cat DP's and then gut OPF of OEM midpipe ?

BP
Quote:
Originally Posted by MR. View Post
That is not going to work. You will change back pressure which will make sure the sensors throw your car in an error.

Also a sport car DP will not fit in the space next to the engine I heard (not 100% sure), so those are not an option, next to the fact that you put too much strain on the OPFs.
Marc - shame you didn't read my post properly as I say the tricks required to code out CEL/error/limp mode are assumed in place and that gutting OPF - same principle as gutting cat pipes - removes the brick blocking the exhaust but looks OEM...

Also sport cats DP not fitting - doubtful else why do LW in Germany offer them for M2Comp ? BP

BP

Quote:
Originally Posted by doughboy View Post
Sport cat DPs re about £2500-3000 compared to under £500 for Decats.

Only problem is non EU mid pipe is £2450 after discount.... Maybe buy used from US guys?
DB - yes LW charge £3k for their catted DP's but the likes of Milltek sell catted DP's for s55 for half this price....BP
BP (or anyone else who can help with this one),

I'm getting the LightWeight system next month, keeping OPFs. I saw recently their sport downpipes are coming in at just under €3,000 as you mentioned, which isn't ideal. Do you know if alternative downpipes can be interchanged with different exhaust systems, i.e. could I use a Milltek DP with the LightWeight exhaust or would they not line up correctly?

Cheers,

Karl
Karl

It's usual for aftermarket DPs to fit stock exhaust and aftermarket exhausts to fit stock DPs.

Safe to assume that aftermarket DPs and aftermarket exhausts are cross compatible.

BP
BP,

I hope that's the case so I don't have to buy LW DPs if I want to go down that route at a later date. Still, I'm not going to sweat it if it's not possible later down the line.

Cheers,

Karl
__________________
2019 HS DCT M2 Competition with Essex AP Racing Radical Pro5000r front and rear BBKs, Bilstein B16s and 763M wheels with Cup 2s
Appreciate 1
Bee Pee1736.00
      03-12-2019, 03:19 AM   #46
doughboy
Major General
doughboy's Avatar
1543
Rep
8,972
Posts

Drives: 2018 M2 Comp 6MT
Join Date: Jan 2009
Location: UK

iTrader: (2)

Quote:
Originally Posted by Karlosm2c View Post
BP (or anyone else who can help with this one),

I'm getting the LightWeight system next month, keeping OPFs. I saw recently their sport downpipes are coming in at just under €3,000 as you mentioned, which isn't ideal. Do you know if alternative downpipes can be interchanged with different exhaust systems, i.e. could I use a Milltek DP with the LightWeight exhaust or would they not line up correctly?

Cheers,

Karl
Yes as previous, as each of these parts will fit with OE exhaust then they all have to line up at the same connecting points and use the same OE fitting, the main connection being the DP to exhaust flange.
Appreciate 0
      03-12-2019, 03:28 AM   #47
doughboy
Major General
doughboy's Avatar
1543
Rep
8,972
Posts

Drives: 2018 M2 Comp 6MT
Join Date: Jan 2009
Location: UK

iTrader: (2)

Quote:
Originally Posted by ingmv View Post
Has anyone tried to remove S1DEA from the VO?

And flash the DME ?
No but i will be playing soon when i get the OPFs off.

I'm interested to find out what the DTCs / fault codes will be. Everyone just says "arrrgh limp mode" but what faults are actually behind it? I've not seen anything more.

It might not just be a emission check as these dont usually cause limps. The sudden drop in exhaust back pressure will also upset the boost control / PWM levels resulting in greater boost for a certain actuator force, so there maybe multiple faults coming up. Remember OPF cars run more boost to compensate which means OPF restriction is significant.

Boost target overshoot used to limp my N54.

Until someone posts a full ISTA diagnostic dump I'm open to all theories...

Last edited by doughboy; 03-12-2019 at 09:48 AM..
Appreciate 0
      03-12-2019, 05:39 AM   #48
Karlosm2c
Lieutenant
Karlosm2c's Avatar
United Kingdom
291
Rep
456
Posts

Drives: M2 Competition
Join Date: Oct 2018
Location: Bedfordshire

iTrader: (0)

Quote:
Originally Posted by doughboy View Post
Yes as previous, as each of these parts will fit with OE exhaust then they all have to line up at the same connecting points and use the same OE fitting, the main connection being the DP to exhaust flange.
Cheers Mike,

That's a relief to hear another person back that up. It means I will have good range of downpipe options should I want to take this route at a later date.
__________________
2019 HS DCT M2 Competition with Essex AP Racing Radical Pro5000r front and rear BBKs, Bilstein B16s and 763M wheels with Cup 2s
Appreciate 0
      09-25-2019, 05:51 PM   #49
F90M5C
First Lieutenant
F90M5C's Avatar
Sweden
155
Rep
317
Posts

Drives: 19 F90 M5C,17 F82 ZCP M4
Join Date: Jan 2015
Location: Sweden

iTrader: (0)

Quote:
Originally Posted by MR. View Post
I will share more when I can with regards to the product idea for the OPF delete. The aim is no more ECU tuning to remove the OPFs.

MR
hey

any new info ?
Appreciate 1
Moris3.00
      09-26-2019, 09:57 AM   #50
MRosth
Private
MRosth's Avatar
Sweden
126
Rep
97
Posts

Drives: M2 Comp
Join Date: Oct 2015
Location: Sweden, Stockholm

iTrader: (0)

Quote:
Originally Posted by F90M5C View Post
hey

any new info ?
Buy a JB4 from Burger Tuning, use their Passive delete function and let go of the OPF filters.

Im running Remus Race and the linkpipe with JB4 with no problems.
I have the new DME software so I cant go any other way atm like BM3
Appreciate 0
      09-27-2019, 04:00 AM   #51
F90M5C
First Lieutenant
F90M5C's Avatar
Sweden
155
Rep
317
Posts

Drives: 19 F90 M5C,17 F82 ZCP M4
Join Date: Jan 2015
Location: Sweden

iTrader: (0)

Quote:
Originally Posted by MRosth View Post
Buy a JB4 from Burger Tuning, use their Passive delete function and let go of the OPF filters.

Im running Remus Race and the linkpipe with JB4 with no problems.
I have the new DME software so I cant go any other way atm like BM3
my M5 Comp. ran without the OPF filters since before the break in service.
my problem is that the car goes into limp mode on the Autobahn and almost never here in sweden( once on a long road trip up north).i guess the JB4 passive delete will only turn off the CEL once its on and will not help preventing the car from going into limp mode, i really don't want to tune the car and was really excited to read that marc might had a solution by now
Appreciate 0
      09-27-2019, 04:34 AM   #52
doughboy
Major General
doughboy's Avatar
1543
Rep
8,972
Posts

Drives: 2018 M2 Comp 6MT
Join Date: Jan 2009
Location: UK

iTrader: (2)

Something I noticed in ISTA diagnostics (if you have it) is you can run recalibration for a new OPF.

I.e. if lets say you had your OPF replaced by BMW the DME needs to re-set it self to the new OPF characteristic.

So I wonder if resetting this with an OPF delete would mean the DME would then except that new back pressure as being "correct" if that makes sense?
Appreciate 2
      09-28-2019, 01:04 PM   #53
MR.
Colonel
MR.'s Avatar
No_Country
4397
Rep
2,856
Posts

Drives: BMW M2 CSL Turbomeister
Join Date: Sep 2013
Location: Travelling / Managing / Writing

iTrader: (0)

Garage List
Quote:
Originally Posted by F90M5C View Post
hey

any new info ?
Yep, the solution is ready for your car. Product will become available really soon and pre-order will start next week!

I have seen it, hold it in my hands and it is ready for F-Series and G-series, not for the M2C yet. That car proves to be a bitch.

Production is now running so that clients can be helped accordingly over the coming weeks.

MR
Appreciate 1
Moris3.00
      10-31-2019, 02:16 PM   #54
Jamieip
Registered
1
Rep
4
Posts

Drives: F56 S 2019
Join Date: Oct 2019
Location: UK

iTrader: (0)

dm

Quote:
Originally Posted by MR. View Post
Yep, the solution is ready for your car. Product will become available really soon and pre-order will start next week!

I have seen it, hold it in my hands and it is ready for F-Series and G-series, not for the M2C yet. That car proves to be a bitch.

Production is now running so that clients can be helped accordingly over the coming weeks.

MR

Please DM me about this solution!
Appreciate 0
      11-01-2019, 08:22 AM   #55
Big Fabri
Second Lieutenant
Big Fabri's Avatar
Italy
95
Rep
251
Posts

Drives: Lamborghini Huracan
Join Date: Mar 2019
Location: Italy

iTrader: (0)

Quote:
Originally Posted by MR. View Post
Quote:
Originally Posted by Billy_BMW View Post
More information on OPF’s here:
https://www.newtis.info/tisv2/a/en/f...tem/1VnbnDH7q9

Seems from some M140/240 forums, limp mode is a hit and miss - some cars have it and some don’t.

If it happens every couple of thousand miles then it’s not the end of the world if you switch the car off and restart.

CEL seems to be triggered by the pressure measurement on the second sensor after the primary cat.

Some people have had mixed results with valved exhaust backboxes, i.e Remus etc.

Either way, I’ll want to find a way to remove them for extra sound. Let’s hope an ECU fix comes out to code the pressure check off. 😉
We need a feature in Bimmercode or in the Awron display to disengage the sensor, called Delete OPF or something.

That will come for sure, but for now it is only a ECU tune!

MR
It's not gonna happen. Bimmercode can't write the engine ecu which is where who opf stuff is in,it can only write control modules
__________________
Appreciate 0
      11-02-2019, 01:46 PM   #56
MR.
Colonel
MR.'s Avatar
No_Country
4397
Rep
2,856
Posts

Drives: BMW M2 CSL Turbomeister
Join Date: Sep 2013
Location: Travelling / Managing / Writing

iTrader: (0)

Garage List
Quote:
Originally Posted by Jamieip View Post
Please DM me about this solution!
Please read this mate: https://f87.bimmerpost.com/forums/sh....php?t=1653857

MR
Appreciate 0
      11-03-2020, 04:10 AM   #57
F87EVO
Major
F87EVO's Avatar
Cyprus
4004
Rep
1,221
Posts

Drives: BMW F87 M2 CS (6MT)
Join Date: Jan 2018
Location: Europa

iTrader: (0)

Garage List
Quote:
Originally Posted by MR. View Post
We need a feature in Bimmercode or in the Awron display to disengage the sensor, called Delete OPF or something.

That will come for sure, but for now it is only a ECU tune!

MR
Hello MR ! I have ordered the AA Midpipe for my M2 CS , so the only way now its the tune ? i dont want to tune my car for more hp , just leave it the same hp but turn off the limp mode. even if the answer is a tune , isnt it just disabling the opf sensor ?
__________________
Sometimes, the simplest recipes, done well, with quality ingredients, are the tastiest, - evo Car of the Year 2020
2020 BMW F87 M2 CS - 6MT - Misano Blue Metallic
Appreciate 0
      11-03-2020, 05:24 AM   #58
Ollie RS
Private
Ollie RS's Avatar
Poland
42
Rep
76
Posts

Drives: BMW M2 Competition
Join Date: Apr 2019
Location: Warsaw

iTrader: (0)

Quote:
Originally Posted by Turbomeister View Post
Hello MR ! I have ordered the AA Midpipe for my M2 CS , so the only way now its the tune ? i dont want to tune my car for more hp , just leave it the same hp but turn off the limp mode. even if the answer is a tune , isnt it just disabling the opf sensor ?
The AK Motion display has a function to disable the OPF filters without a tune
Appreciate 1
Moris3.00
      11-03-2020, 05:25 AM   #59
F87EVO
Major
F87EVO's Avatar
Cyprus
4004
Rep
1,221
Posts

Drives: BMW F87 M2 CS (6MT)
Join Date: Jan 2018
Location: Europa

iTrader: (0)

Garage List
Quote:
Originally Posted by Ollie RS View Post
Quote:
Originally Posted by Turbomeister View Post
Hello MR ! I have ordered the AA Midpipe for my M2 CS , so the only way now its the tune ? i dont want to tune my car for more hp , just leave it the same hp but turn off the limp mode. even if the answer is a tune , isnt it just disabling the opf sensor ?
The AK Motion display has a function to disable the OPF filters without a tune
Yeah but do i have to put the AK motion into the ac vent?
__________________
Sometimes, the simplest recipes, done well, with quality ingredients, are the tastiest, - evo Car of the Year 2020
2020 BMW F87 M2 CS - 6MT - Misano Blue Metallic
Appreciate 0
      11-03-2020, 05:40 AM   #60
Ollie RS
Private
Ollie RS's Avatar
Poland
42
Rep
76
Posts

Drives: BMW M2 Competition
Join Date: Apr 2019
Location: Warsaw

iTrader: (0)

Quote:
Originally Posted by Turbomeister View Post
Yeah but do i have to put the AK motion into the ac vent?
I mounted mine in the air vent but you can install it wherever you want (i've seen some mounted below the centre console). Mine was purchased mainly for its additional functions and data display but it's also a good solution for the OPF delete without having to tune the car.
Appreciate 1
F87EVO4004.00
      11-03-2020, 05:42 AM   #61
F87EVO
Major
F87EVO's Avatar
Cyprus
4004
Rep
1,221
Posts

Drives: BMW F87 M2 CS (6MT)
Join Date: Jan 2018
Location: Europa

iTrader: (0)

Garage List
Quote:
Originally Posted by Ollie RS View Post
Quote:
Originally Posted by Turbomeister View Post
Yeah but do i have to put the AK motion into the ac vent?
I mounted mine in the air vent but you can install it wherever you want (i've seen some mounted below the centre console). I purchased mine mainly for its additional functions and data display but it's also a good solution for the OPF without having to tune the car
Yes , what if instead of tuning the car and making a remap for performance , to just deactivate the opf sensors throught the tune? So 0 performance gains , just deactivate the Opf sensors. ? Will it work?
__________________
Sometimes, the simplest recipes, done well, with quality ingredients, are the tastiest, - evo Car of the Year 2020
2020 BMW F87 M2 CS - 6MT - Misano Blue Metallic
Appreciate 0
      11-03-2020, 08:05 AM   #62
MR.
Colonel
MR.'s Avatar
No_Country
4397
Rep
2,856
Posts

Drives: BMW M2 CSL Turbomeister
Join Date: Sep 2013
Location: Travelling / Managing / Writing

iTrader: (0)

Garage List
Quote:
Originally Posted by Turbomeister View Post
Yes , what if instead of tuning the car and making a remap for performance , to just deactivate the opf sensors throught the tune? So 0 performance gains , just deactivate the Opf sensors. ? Will it work?
Yep driving with it for two years now!

MR
Appreciate 0
      11-04-2020, 05:20 PM   #63
kart driver
Captain
567
Rep
658
Posts

Drives: M & GT
Join Date: Jul 2018
Location: Europe

iTrader: (0)

Is the installation of the AK MOTION module and then deactivating the OPF an easy job?

I mean would buying the module from a reputable seller and then letting a shop, which have never done the install before, be a reasonable decision?
Appreciate 0
      11-05-2020, 12:51 PM   #64
NISFAN
Major General
NISFAN's Avatar
United Kingdom
3486
Rep
9,709
Posts

Drives: BMW M2
Join Date: Aug 2012
Location: Bedford UK

iTrader: (0)

I wonder if relocating the sensor tubes from after the catalytic converter to before, will fool the electronics by reporting back a pressure reading?

For those that don't know, the OPF fitted cars have a pressure measuring sensor in each exhaust. The pressure sampling tube is placed after (downstream) of the primary CAT, but before the 2ndary CAT / OPF canister. So it effectively measures exhaust pressure just prior to the OPF /CAT2 system. I guess when it sees a high reading threshold, it triggers an active regeneration. But at all times it needs to see some kind of reading as a test. That's why a total OPF delete triggers CEL/LIMP.

My thinking about how to fool it is in three forms. And by the way, I'm looking at replacing the OPF canister mid pipe to earlier style 2nd CAT type, not a full delete. Some of the techniques below could work for full delete too.

1.) move the sensor to pre primary CAT. As long as the pressure isn't high enough normally in this area (between turbo outlet and CAT elements) to trigger active regen, we should be fine.

2.) Fit an elbow pointing upstream on the sensor tubes. Normally the sensor is Tee'd into the exhaust at 90 degrees. This measures static pressure only. If we added an elbow facing the exhaust gas stream, we get a dynamic pressure (static + gas velocity). So with OPF removed, the pressure reading will increase with revs (as it will with the OPF in situ). Different size elbow bores can be used to modify the dynamic part.

3.) fit some type of electronic gain chip to the sensor. Like a JB+. There will be some pressure in the exhaust even with 2ndary CATs only, we just need to amplify that signal into the right range. The sensor itself is a 0-5v analogue unit, much like the boost pressure sensors, hence the reference to JB+
Appreciate 0
      11-22-2020, 01:06 PM   #65
Mark 1M
Lieutenant
Mark 1M's Avatar
United Kingdom
349
Rep
424
Posts

Drives: M2
Join Date: Apr 2015
Location: Scotland

iTrader: (0)

I have had opf removed for over 6 months no cel or limp mode it sounds a lot better
Appreciate 0
      11-22-2020, 02:32 PM   #66
prompt
Car Designer
prompt's Avatar
United Kingdom
292
Rep
263
Posts

Drives: M2C
Join Date: Oct 2015
Location: Midlands UK

iTrader: (0)

Quote:
Originally Posted by Mark 1M View Post
I have had opf removed for over 6 months no cel or limp mode it sounds a lot better
Did you do a remap or something else?
How many miles have you done since removing it?
Do you drive the car hard,I mean revving over 5k rmp?
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 06:53 AM.




m2
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST