Cel ... Lean Both Banks ...

[apexlocator]

I have not gotten the lean codes again after Mission Performance tweaked my tune to accommodate for the RK intakes and DPs (which were installed after my initial tune).

[ur20v]

Where ar your fuel trims at and how are your fuel pressures?

[AWF10M5]

Have vrsf catless downpipes and front grill intakes with no tune

Getting the 118110 code. It’s cold here now around 32F or 0C

2 new maf, 2 new o2, new plugs and coils were put in.

Is this just because of the intake and downpipes?

Is it okay to ignore thisncode ? Only option is to be tuned?

[MissionPerformance]

You need to see your multiplicative adaptions and if you are withing 20%, you are fine aside from having the CEL pop up now and then.

Running lean on these cars is a little miss understanding that some people face. These cars can adapt to run +/-34% fueling if needed to be, though CEL will get triggered when they pass 15/18%. What that means is that if you fill a little too much of E85, your DME might need to add 20% of fueling to maintain proper AFR. That is completely safe and your car is in no way running "Lean" but you will get a code for "lean" condition since the adaptation passed the threshold.

[TheHouseWon]

Subscribing, great info!

Got the 118010 code. Mixture too lean. HCPerformance tune via bm3.

[azndrunk74]

Originally Posted by TheHouseWon

Subscribing, great info!

Got the 118010 code. Mixture too lean. HCPerformance tune via bm3.

I’m guessing you have intakes and dps too?

[TheHouseWon]

Originally Posted by azndrunk74

I’m guessing you have intakes and dps too?

Yes. I need to log and ask Halim what's going on.

[Mr. M6]

Originally Posted by TheHouseWon

Yes. I need to log and ask Halim what's going on.

i got code 118111 bank 2 mixture too rich , intake and dp with ots stage 2, i clear the codes and gone, i will see if that coming again, but what i have to check if came again...

[Pikey Motorsports]

I don’t have these issues with bm3 and intakes

[TheHouseWon]

Oil from K&N can affect the MAF causing codes, so check that there is no oil in the intakes and clean the maf's with special cleaner

[ByronUT_M6]

Originally Posted by TheHouseWon

Yes. I need to log and ask Halim what's going on.

Did you ever get an answer on this?

I'm curious because my check engine light popped on as soon as I started my car this morning and last time this happened it was for mixture too lean in bank 1 but I cleaned my MAF's and it went away now 2 months later it's back. I'm on stock tune and only have muffler delete and front grille mount intakes.

[TheHouseWon]

Could be colder denser air and/or oil in the MAF (but you cleaned so may be something else).

Havent logged so havent sent anything to tuner.

[RAFiK - BMWClubUAE]

[Manny G]

I'm getting 118010 even after cleaning my MAFs and also replacing them with new inserts.

Its been in and out of the dealership at least 5 times for the CEL,.. they shotgunned the repair and still didnt fix it.

The replaced 8 injectors, 8 sparkplugs, 8 coil packs, both cat converters and also updated the software.

The MAFs were as old as the car (2013, 62k miles) and I'm guessing the O2 sensors are also. I'll be replacing them next if I cant come up with any other reason. I monitored the STFT and LTFT values via Carly while connected to OBD,.. LTFT on one bank is around 24-25, the other is around 21-22.. before the MAF cleaning/replacing, they were both down in the 10s

Car has no mods, factory intake.. only carbon filter delete.

[Dwaynos]

Originally Posted by Manny G

I'm getting 118010 even after cleaning my MAFs and also replacing them with new inserts.

Its been in and out of the dealership at least 5 times for the CEL,.. they shotgunned the repair and still didnt fix it.

The replaced 8 injectors, 8 sparkplugs, 8 coil packs, both cat converters and also updated the software.

The MAFs were as old as the car (2013, 62k miles) and I'm guessing the O2 sensors are also. I'll be replacing them next if I cant come up with any other reason. I monitored the STFT and LTFT values via Carly while connected to OBD,.. LTFT on one bank is around 24-25, the other is around 21-22.. before the MAF cleaning/replacing, they were both down in the 10s

Car has no mods, factory intake.. only carbon filter delete.

Don't throw more parts at it until you know they are faulty.

Is the engine running lean on both banks?

It's unlikely to have more than 1 faulty o2 sensor. Judging by your fuel trim, the ecu is adding fuel to compensate for a lean condition which I'm sure you already knew. Providing you have checked everything else you can add propane or another source of fuel to the intake to see if the sensors respond and the ecu alters fuel trims to suit. (Do this at your own risk, don't add to much fuel if it's in liquid form, I.e. brake cleaner.)

I don't think the M5 has intake vacuum so the chances of a vacuum leak causing this are unlikely. You could have a fuel pressure problem. I don't want to become a keyboard mechanic but hoping to give you a few pointers before you go changing anymore parts.

[Manny G]

Originally Posted by Dwaynos

Don't throw more parts at it until you know they are faulty.

Is the engine running lean on both banks?

It's unlikely to have more than 1 faulty o2 sensor. Judging by your fuel trim, the ecu is adding fuel to compensate for a lean condition which I'm sure you already knew. Providing you have checked everything else you can add propane or another source of fuel to the intake to see if the sensors respond and the ecu alters fuel trims to suit. (Do this at your own risk, don't add to much fuel if it's in liquid form, I.e. brake cleaner.)

I don't think the M5 has intake vacuum so the chances of a vacuum leak causing this are unlikely. You could have a fuel pressure problem. I don't want to become a keyboard mechanic but hoping to give you a few pointers before you go changing anymore parts.

The engine ran rough prior to the MAF cleaning and replacement.. I'm sure that was part of the problem at first. When I cleaned the MAFs, I found one that had oil residue on it.. CEC cleaned it right off.

Dealer replaced the crankcase vent tubes noting a crack was found on one after a smoke test. They smoke tested the system and did not find any other leaks.

Right now only 1 bank is faulting lean.. occasionally i do see an error on bank 2 but it clears up on its own. The bank 1 lean comes back immediately after clearing

[Dwaynos]

Originally Posted by Manny G

The engine ran rough prior to the MAF cleaning and replacement.. I'm sure that was part of the problem at first. When I cleaned the MAFs, I found one that had oil residue on it.. CEC cleaned it right off.

Dealer replaced the crankcase vent tubes noting a crack was found on one after a smoke test. They smoke tested the system and did not find any other leaks.

Right now only 1 bank is faulting lean.. occasionally i do see an error on bank 2 but it clears up on its own. The bank 1 lean comes back immediately after clearing

When you say immediately, do you mean as soon as you strike the engine up again after clearing? What do the fuel trims do after you've cleared the codes? Is there an option to reset the fuel trims or an o2 learn? Try resetting if possible although the ecu should correct fueling if you have fixed a problem.

As it's on one bank only then you could have a faulty o2. The way to check this is by looking at the live reading given from the o2s on that bank and add fuel/propane to the cylinders on that bank and check for sensor response using live data.

[Manny G]

Originally Posted by Dwaynos

When you say immediately, do you mean as soon as you strike the engine up again after clearing? What do the fuel trims do after you've cleared the codes? Is there an option to reset the fuel trims or an o2 learn? Try resetting if possible although the ecu should correct fueling if you have fixed a problem.

As it's on one bank only then you could have a faulty o2. The way to check this is by looking at the live reading given from the o2s on that bank and add fuel/propane to the cylinders on that bank and check for sensor response using live data.

When I clean the 118010 fault, it comes back on when I start the engine. Occasionally I will see 118110 fault which is the same fault for the bank2/ECU2, but I am able to clear it and not have it come back immediately.

I dont have the capability to reset mixture adaptations.

If I do not find a leak anywhere, then I am left to think that either the O2 sensors are not reading correctly or the fuel tank vent hoses & sensors will need to be replaced.

I checked both DTC faults on http://bmwfault.codes/ , and they're general condition is linked to "- Tank ventilation system not active."

[Manny G]

Following up to my last post,... turned out that there were no leaks. I had the engine smoke tested, nothing found.

Pretty sure the lingering CEL was related to old adaptations that I could not reset myself since I did not have a tool capable of clearing them.

I took it to a shop that cleared them with the Autologic, and viola! no more CEL. It used to turn on immediately after clearing and restarting the car, now it does not turn on at all anymore.

So summary, clearing adaptations when getting those lean codes if no leaks are present should be all you need. Also worth giving the MAFs a cleaning too.