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      05-07-2026, 09:39 AM   #1
narkotic
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Code 2786 - Fuel pressure sensor and NRW Fuel Filter

Hi all-

This is more focused around those that opted to use a NRW fuel filter system. Since installing this, and replacing the low pressure sensor (with adapter) I keep getting a code of 2786. "Plausibility, fuel-pressure sensor, to mechanical pressure regulator".

This code doesn't seem to throw a CEL, so you don't really see it until you scan for codes using something like protool or the likes.

Checking in here - can those that have this fuel filter scan to see if you have this code? I recently installed a Harrop SC and this code worries me, but maybe it's innocuous. Or, maybe it's related to the fuel pressure sensor since I unfortunately changed two things at once. I did find out, after the case, that when I bought the new sensor I got it from ECS and it recommended the lower cost option , albeit "viable alternative" at a much lower cost. Perhaps I try the actual BMW part number sensor which is of course 3x the cost.

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      05-11-2026, 04:24 PM   #2
narkotic
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Removed the fuel filter today, problem gone. If anyone runs into this, ditch the filter.
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      05-11-2026, 06:41 PM   #3
Redd
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Pls feedback to NRW
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      05-11-2026, 06:59 PM   #4
narkotic
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Yeah, did that. They weren't interested and never responded to me. Not the best CS..
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      05-12-2026, 09:50 PM   #5
e36mikee
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wow interesting. so i installed an NRW filter a few weeks ago and then a new low press sensor very recently also(barely any miles since either of this as its weekend car). i was playing around with bimmerlink yesterday and saw code 2786 and 27E6 stored. i thought it was just from when i installed the new sensor and pulled the fuel pump fuse to purge the system. figured it just stored it and i hadnt noticed or reset it yet. today i reset those codes and then drove the car around, did some logs, and filled the tank. about a 15 minute drive. got home, and no codes yet. will keep an eye and see if it comes back.
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      05-13-2026, 09:31 AM   #6
narkotic
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Get rid of it. I saw your post in the other thread. Once I pulled mine the car ran much better, and no more codes.
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      05-13-2026, 11:18 AM   #7
e36mikee
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Quote:
Originally Posted by narkotic View Post
Get rid of it. I saw your post in the other thread. Once I pulled mine the car ran much better, and no more codes.
Yes so the pressure issues i believe may just be related to the regulator failing. Im having the pressure falling off also overnight etc. So cold starts have a slightly long crank. Its a good question though like, did adding the fuel filter make the regulators problems more apparent? I dont have before or after data to confirm. I havent noticed any performance issues and the intermittent .10 bar below pressure which possibly is the failing regulator or just sensor noise. Ill be doing more testing but i dont believe any actual starving is going on. I could somewhat easily just remove it and test.. but i think either way the regulator is likely bad and needs to be replaced anyway. The filter has like 250 gph and i believe the s65 only requires like 40? Im not sure the effects on pressure the filter could have assuming everything else is working.
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      05-13-2026, 01:35 PM   #8
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Quote:
Originally Posted by narkotic View Post
Get rid of it. I saw your post in the other thread. Once I pulled mine the car ran much better, and no more codes.
Quote:
Originally Posted by e36mikee View Post
Yes so the pressure issues i believe may just be related to the regulator failing. Im having the pressure falling off also overnight etc. So cold starts have a slightly long crank. Its a good question though like, did adding the fuel filter make the regulators problems more apparent? I dont have before or after data to confirm. I havent noticed any performance issues and the intermittent .10 bar below pressure which possibly is the failing regulator or just sensor noise. Ill be doing more testing but i dont believe any actual starving is going on. I could somewhat easily just remove it and test.. but i think either way the regulator is likely bad and needs to be replaced anyway. The filter has like 250 gph and i believe the s65 only requires like 40? Im not sure the effects on pressure the filter could have assuming everything else is working.


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      05-13-2026, 01:40 PM   #9
e36mikee
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Quote:
Originally Posted by smokinjoe64 View Post

Thanks for bringing that to my attention. So essentially im probably correct to assume the filter brought light to my failing regulator. I believe the pump is still good because pressures on prime/wot etc seem fine but i have the random 5-10second 2.85-2.9 bar pressure when the target is 3 idling and what not. And then leaking pressure when cars been sitting for some hours.

Edit : So upon more research and your post, there is no regulator by itself we just have the transfer unit and the main pump. So i should probably go ahead and replace those as they will likely die soon enough as highlighted by the filter. 50k mile 2010 car.

Last edited by e36mikee; 05-13-2026 at 02:31 PM..
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