[dpatton]

I have a 2014 BMW 435i xDrive with 28k miles on it. I purchased it about 1 year ago with only 18k miles on it. Since purchasing it I have done the following mods:

BMS Charge Pipe
BMS Performance Intake
MAD Race Intercooler
FTP Boost Pipe
CTS Turbo Catted Downpipe
BM3 Stage 2 Tune

The car has been running great. The only CEL code I got was shortly after the downpipe was installed. It was for 128901 – Lambdasonde 1 Bank 1, dynamics: slow response. I cleared the code and never had any issues after that (March 2023)

Yesterday, while trying to pass a slow car my car stuttered, lost power and went into “drive train malfunction.” I pulled over in a parking lot to read the codes.

123511 – Electric Wastegate, wastegate flap: stiff
140402 – Combustion misfires, cylinder 4: harmful to exhaust gases after starting
140002 – Combustion misfires, several cylinders: harmful to exhaust gases after starting
140401 – Combustion misfires, cylinder 4: Injection is switched off
140001 – Misfires, multiple cylinders, Injection is switched off
140410 – Misfires, cylinder 4: detected
140010 – Misfires, multiple cylinders: detected
140011 – Combustion misfires: Injection shutdown – Inactive
231501 - Error log entry: send buffer full

I replaced all the spark plugs and ignition coils and cleared the codes. I also flashed back to the stock tune. The car no longer goes into drive train malfunction and does not throw any CEL codes but does not run right. The car has a rough idle and stutters/jerks when I accelerate.

During idle, I pulled the MAF sensor plug which results in a CEL and no change to the rough idle. The codes indicate I have a misfire in cylinders 2 and 6. I tried swapping coils and always get the same misfires on 2 and 6.

Could this be an injector issue? Any help is appreciated.

Thanks!

[5w20]

Originally Posted by dpatton

I have a 2014 BMW 435i xDrive with 28k miles on it. I purchased it about 1 year ago with only 18k miles on it. Since purchasing it I have done the following mods:

BMS Charge Pipe
BMS Performance Intake
MAD Race Intercooler
FTP Boost Pipe
CTS Turbo Catted Downpipe
BM3 Stage 2 Tune

The car has been running great. The only CEL code I got was shortly after the downpipe was installed. It was for 128901 – Lambdasonde 1 Bank 1, dynamics: slow response. I cleared the code and never had any issues after that (March 2023)

Yesterday, while trying to pass a slow car my car stuttered, lost power and went into “drive train malfunction.” I pulled over in a parking lot to read the codes.

123511 – Electric Wastegate, wastegate flap: stiff
140402 – Combustion misfires, cylinder 4: harmful to exhaust gases after starting
140002 – Combustion misfires, several cylinders: harmful to exhaust gases after starting
140401 – Combustion misfires, cylinder 4: Injection is switched off
140001 – Misfires, multiple cylinders, Injection is switched off
140410 – Misfires, cylinder 4: detected
140010 – Misfires, multiple cylinders: detected
140011 – Combustion misfires: Injection shutdown – Inactive
231501 - Error log entry: send buffer full

I replaced all the spark plugs and ignition coils and cleared the codes. I also flashed back to the stock tune. The car no longer goes into drive train malfunction and does not throw any CEL codes but does not run right. The car has a rough idle and stutters/jerks when I accelerate.

During idle, I pulled the MAF sensor [...]

The codes indicate cylinder 4 is the problem child, but you said you are having issues with cylinders 2 & 6?

[dpatton]

Yes, after replacing all spark plugs and coils the problem with 4 went away. Then 2 and 6 started misfiring. No CELs but very rough idle and stuttering when I accelerate.

[LA1Z24]

Did you use a proper BMW spark plug socket, or a regular socket with a universal on it? There's a high chance you cracked the plug if you used the wrong socket.

[dpatton]

I used a thin walled socket and torqued the plugs to 17 ft pounds. I’m going to pull them and inspect them to see if they are cracked. Thanks.

[LA1Z24]

Originally Posted by dpatton

I used a thin walled socket and torqued the plugs to 17 ft pounds. I’m going to pull them and inspect them to see if they are cracked. Thanks.

Thin walled socket means nothing. Did you use a BMW spark plug socket that has the integrated universal joint? If you used a normal plug socket, with a detachable universal, the plugs can crack easily.

[dpatton]

No, I did not. I’m going to look into getting this specific tool. Thanks.

[n55david]

You need a thin walled socked and a swivel.. you don't need the bmw one... but you need something. You can actually damaged a plug and the valve cover..

You have an issue, likely if changing everything cause a new issue it's something you did. Messed up a plug, bad connection etc etc

[dpatton]

LA1Z24 and n55david - Thank you both for the help. I purchased a universal joint and 2 new spark plugs. I installed them with the universal joint and that fixed the problem.

There were no physical cracks or damage on the other plugs but I must have damaged them when I installed them without the universal joint.

My car is running great again. Thanks again!

[LexsF30n55]

hi i got the same issues well when i start my car up the rpm goes up to 2k and drops down and the car stalls getting misfire codes as well
101F01 - Air mass system, plausibility: calculated air volumes in air intake system implausible.
108001 - Intake air temperature sensor, electrical: Short circuit to B+.
118002 - Mixture control: Fuel-air mixture too rich.
Knowledg 140002 - Combustion misfires, several cylinders: Damaging exhaust gas after starting up.
140010 - Combustion misfires, several cylinders: detected.
FAQ
140302 - Combustion misfire, cylinder 3: Damaging exhaust gas after starting up.
140310 - Combustion misfire, cylinder 3: detected.
140402 - Combustion misfire, cylinder 4: Damaging exhaust gas after starting up.
Connect G
140410 - Combustion misfire, cylinder 4: detected.

[thejeremyman9]

Originally Posted by LexsF30n55

hi i got the same issues well when i start my car up the rpm goes up to 2k and drops down and the car stalls getting misfire codes as well
101F01 - Air mass system, plausibility: calculated air volumes in air intake system implausible.
108001 - Intake air temperature sensor, electrical: Short circuit to B+.
118002 - Mixture control: Fuel-air mixture too rich.
Knowledg 140002 - Combustion misfires, several cylinders: Damaging exhaust gas after starting up.
140010 - Combustion misfires, several cylinders: detected.
FAQ
140302 - Combustion misfire, cylinder 3: Damaging exhaust gas after starting up.
140310 - Combustion misfire, cylinder 3: detected.
140402 - Combustion misfire, cylinder 4: Damaging exhaust gas after starting up.
Connect G
140410 - Combustion misfire, cylinder 4: detected.

Start with the first two, sounds like you might have a sensor or wiring issue