Running a decat

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Ash J
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Running a decat

Post by Ash J » Mon Mar 19, 2018 12:22 pm

Blew the charge pipe on my M135 last week (running a remap) so had some ML Performance uprated ones fitted.

At the same time, I had a catless downpipe fitted, along with a DV+ (uprated diverter valve part).

I will be going to back to my tuner soon to have the map tweaked since I now have decat etc (and also an uprated intercooler this week), but I have noticed when sitting at a constant speed on the motorway, there is sometimes a stutter, almost like a misfire, so it jolts and then is fine again. It's only momentarily and can do it a few times when cruising/partial throttle. Also, the engine management light sometimes comes on, obviously due to decat, and this will be coded out when I go back to have map tweaked.

Just wanted to check.... I assume having the decat fitted is what is causing this? Was fine before. I don't mind living with it until I go back to have map tweaked.

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Ash

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GeoffCollins
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Re: Running a decat

Post by GeoffCollins » Mon Mar 19, 2018 12:24 pm

I have a decat, did a 200 mile drive yesterday and no stuttering? Might be the map?

Also the light should be coded out, mine gets cancelled from the JB4
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, M4 Front Pads, MeisterR Coilovers, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

Ash J
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Re: Running a decat

Post by Ash J » Mon Mar 19, 2018 12:48 pm

Could well be the map yes. I had it done before decat was fitted etc. Either that, or could be the uprated diverter part.

I do not have a JB4 so can't just code it out - but DMS who did my remap said I can take it back once decat fitted and they can code it out/alter the parameters.

I have just got a Vgate iCar to use with Bimmercode - so for time being I will be able to turn the light off with that.

Blind Pugh
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Re: Running a decat

Post by Blind Pugh » Mon Mar 19, 2018 1:17 pm

Ash

Was the remap an off the shelf or bespoke ie mapped to suit yr car.

Either way adding hardware after a remap means gains - from your new parts - may well be limited.

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Ash J
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Re: Running a decat

Post by Ash J » Mon Mar 19, 2018 2:04 pm

I'm not entirely sure, it might just be off the shelf - was done by DMS, but will check.

As I say I will be going back to have it tweaked seeing as new parts have been fitted after having the map done.

Xenoous
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Re: Running a decat

Post by Xenoous » Mon Mar 19, 2018 2:09 pm

Why do people insist on running decats when it's completely against the law and means your insurance is null and void? It really doesn't make sense to me...
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Ash J
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Re: Running a decat

Post by Ash J » Thu Mar 22, 2018 9:11 am

Car is definitely not running right as I mentioned in my first post.

As I say, the engine management light is on, of course because of the decat.

But I also get a drivetrain error message on the iDrive everytime I drive the car, which says...

'Possible to continue journey. Full performance not available. Have the problem checked by your Service Partner.'

It is definitely not performing at 100% and feels like it is low on power.

Was running perfect before I blew the chargepipe. When I got the chargepipe upgraded to an ML Performance one, I also had a decat fitted and an uprated GFB DV+. Since then I have these problems.

The car is going back to my trusted garage soon to have a CSF intercooler fitted (waiting for it to arrive) and an oil service. They are going to plug the car in for me to see what faults are showing at the same time.

I will then be going back to DMS to have the car remapped to suit all the additional parts I have had fitted... when I first had the car remapped it was stock. So perhaps this is what is giving me the running issues, but the drivetrain error seems strange.

Anyway, ultimately I should have an idea what is wrong when it goes back to have the intercooler fitted and a check over, just wanted to know if anybody has had similar problems before!

Thanks

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Re: Running a decat

Post by Blind Pugh » Thu Mar 22, 2018 9:18 am

Ash J wrote:
Thu Mar 22, 2018 9:11 am
Car is definitely not running right as I mentioned in my first post.

As I say, the engine management light is on, of course because of the decat.

But I also get a drivetrain error message on the iDrive everytime I drive the car, which says...

'Possible to continue journey. Full performance not available. Have the problem checked by your Service Partner.'

It is definitely not performing at 100% and feels like it is low on power.

Was running perfect before I blew the chargepipe. When I got the chargepipe upgraded to an ML Performance one, I also had a decat fitted and an uprated GFB DV+. Since then I have these problems.

The car is going back to my trusted garage soon to have a CSF intercooler fitted (waiting for it to arrive) and an oil service. They are going to plug the car in for me to see what faults are showing at the same time.

I will then be going back to DMS to have the car remapped to suit all the additional parts I have had fitted... when I first had the car remapped it was stock. So perhaps this is what is giving me the running issues, but the drivetrain error seems strange.

Anyway, ultimately I should have an idea what is wrong when it goes back to have the intercooler fitted and a check over, just wanted to know if anybody has had similar problems before!

Thanks
Boost leak from CP or DV+ ??
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GeoffCollins
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Re: Running a decat

Post by GeoffCollins » Thu Mar 22, 2018 9:42 am

Xenoous wrote:
Mon Mar 19, 2018 2:09 pm
Why do people insist on running decats when it's completely against the law and means your insurance is null and void? It really doesn't make sense to me...
Change it out when going to the track or show :)
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, M4 Front Pads, MeisterR Coilovers, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

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Re: Running a decat

Post by GeoffCollins » Thu Mar 22, 2018 9:45 am

Ash J wrote:
Thu Mar 22, 2018 9:11 am

But I also get a drivetrain error message on the iDrive everytime I drive the car, which says...

'Possible to continue journey. Full performance not available. Have the problem checked by your Service Partner.'

It is definitely not performing at 100% and feels like it is low on power.
I had this drivetrain error a little while back, I put it down to some bad fuel, filled up at a different petrol station and it went away,

This will also limit the power the the engine makes, almost like a limp mode, try a different fuel, maybe some fuel cleaner stuff too

Try the simple things first

(learnt this on another car when basically changed every part and it turned out the be the boost guage that wasn't working!)
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, M4 Front Pads, MeisterR Coilovers, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

Ash J
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Re: Running a decat

Post by Ash J » Thu Mar 22, 2018 3:38 pm

GeoffCollins wrote:
Thu Mar 22, 2018 9:45 am

I had this drivetrain error a little while back, I put it down to some bad fuel, filled up at a different petrol station and it went away,

This will also limit the power the the engine makes, almost like a limp mode, try a different fuel, maybe some fuel cleaner stuff too

Try the simple things first

(learnt this on another car when basically changed every part and it turned out the be the boost guage that wasn't working!)
Don't think it is bad fuel. I have filled up two or three times since having the car back (about £20 each time) and always Shell V Power. Never been a fan of using a fuel cleaner additive or anything like that.

I shall try looking for boost leak and check the DV+ first like BP mentioned, and if it is still then start looking at other possibilities.
Blind Pugh wrote:
Thu Mar 22, 2018 9:18 am

Boost leak from CP or DV+ ??
It is possible. I shall ask for this to be checked when it goes in for intercooler to be fitted.

Blind Pugh
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Re: Running a decat

Post by Blind Pugh » Thu Mar 22, 2018 4:06 pm

Ash J wrote:
Thu Mar 22, 2018 3:38 pm

I shall try looking for boost leak and check the DV+ first like BP mentioned, and if it is still then start looking at other possibilities.
Blind Pugh wrote:
Thu Mar 22, 2018 9:18 am

Boost leak from CP or DV+ ??
It is possible. I shall ask for this to be checked when it goes in for intercooler to be fitted.
If you live in soft water area - mix up a soapy water solution in small spray bottle and then apply it liberally around CP joints & fittings [and DV although tricker to access TBH] then start her up and look for any bubbles
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