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01-26-2014LAST POST
code details

misfire with emissions deterioration cyl 1/ engine misfire with emissions deterioration cyl 1

code 2b42

I get an occasional hesitation, like a misfire. ordered new plugs, you guys think i need a new coil?

i was going to get in there and switch coils to see if it follows. any other help is appreciated.
I dont know tbh but looking at the sticky above:

2B41 - P0300 (one less)

http://www.m3post.com/forums/showpost.php?p=15283428&postcount=29

2B41 - P0300
Information saved in DME
Fault code 2B41 - P0300
Fault text Misfire with cutout, several cylinders
Fault description Random/Multiple Cylinder Misfire Detected
Condition for fault identification Test condition: Miss capable of damaging cat on multiple cylinders
Terminal condition: Terminal 15
Voltage condition: none
Condition for fault memory entry Varies according to load and rpm
Action in service Note selective logged error codes related to individual cylinders
Fault effect and breakdown warning CC message
Engine speed limited
Reduced power
MIL after engine runs 2x
Rough idle
Driver information Warning light: MIL, EML, CC message, backup program
Service instruction None
engine runs perfect just get a slight hiccup sometimes. like a coil/plug is bad
ok perhaps attempt2 :) simple google:

2B42 Combustion misfire with emissions deterioration cyl 1

if its just 1 cylinder could be spark, if multiple could be ICV (inlet control valve).

but ill let the more experienced members confirm/deny.
could also be injector if one cylinder.
2B42 - P0301, Post-33

It looks like P0301 maps to multiple BMW codes. That makes sense because I would expect BMW codes to be more specific than a generic "misfire cylinder 1" P0301 error.

[btable=100][btrhead=FFFFFF][btd]2B42 - P0301[/btd][btd][/btd][/btrhead][btrhead=FFFFFF][btd]Information saved in[/btd][btd]DME[/btd][/btrhead][btrhead=FFFFFF][btd]Fault code[/btd][btd]2B42 - P0301[/btd][/btrhead][btrhead=FFFFFF][btd]Fault text[/btd][btd]Misfire impairing exhaust emission, cyl. 1[/btd][/btrhead][btrhead=FFFFFF][btd]Fault description[/btd][btd]Cylinder 1 Misfire Detected[/btd][/btrhead][btrhead=FFFFFF][btd]Condition for fault identification[/btd][btd]Test condition: No spark detected in ionic current signal[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]Terminal condition: Terminal 15[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]Voltage condition: none[/btd][/btrhead][btrhead=FFFFFF][btd]Condition for fault memory entry[/btd][btd]Varies according to load and rpm[/btd][/btrhead][btrhead=FFFFFF][btd]Action in service[/btd][btd]1. Check spark plug, interchange with other plug or replace to localize fault[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]2. Exchange ignition coil with another coil to localize fault, replace as indicated.[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]3. Check plug and wiring harness to ignition coil.[/btd][/btrhead][btrhead=FFFFFF][btd]Fault effect and breakdown warning[/btd][btd]CC message[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]Engine speed limited[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]Reduced power[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]MIL after engine runs 2x[/btd][/btrhead][btrhead=FFFFFF][btd][/btd][btd]Rough idle[/btd][/btrhead][btrhead=FFFFFF][btd]Driver information[/btd][btd]Warning light: MIL[/btd][/btrhead][btrhead=FFFFFF][btd]Service instruction[/btd][btd]None[/btd][/btrhead][/btable]
changing out coil and plug tomorrow. ill keep you guys updated
Giorgia wrote  
changing out coil and plug tomorrow. ill keep you guys updated
I would first move the coil to see if the fault moves.
Mike Benvo wrote
I would first move the coil to see if the fault moves.
Okay so i moved the coil and also inspected the spark plug. i really dont know what im looking at anyway lol. So i turned the car and and checked for any codes and nothing was present :mad0259:

When i removed the coil it was on there tight and the spark plug also, so there wasent anything loose that i could see. im going to assume the coil is going bad but why would it work in anther port....... anyway im going to change all the plugs and replace that coil.

Anyway lets see if anything comes back

I should have added that no codes came up on the car itself. i ran the BMWHAT APP with the bluetooth scanner and it found it. was also able to code the car. thing is awesome
drove around all day with no codes or hesitations/misfires. im going to go ahead and change the plugs and that one coil anyway. So we now know that code is either a coil or plug and nothing else.
Giorgia wrote
Nice!!! thanks for posting that. guess my code could be just the spark plug then.
If you are over 37k miles on the same plugs, most likely they are the culprit.
So all my parts came in and for some reason i decide to check the glove compartment and i find all the service history........

So look what i find.... my code said cyl. 1 misfire because the dealer took it out of 2 and put it in one to see if the problem followed hahahhaah. so it turned out to be a failing coil. All the spark plugs were just replaced.

Spark plugs will go for sale lol. can belive the lazy dealer didnt just change that coil.....

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Apparently the fault never returned after they replaced the spark plugs and swapped them at the same time. The customer never brought the car back for the warning, and them appears to have sold it. Unless you just don't remember having the issue with your own car, but that doesn't seem to be the case. Ironically this appears to be the same diagnostic path you were going to take here. Speaking of lazy, who isn't familiar with their own service history?
MilehighM3 wrote
Apparently the fault never returned after they replaced the spark plugs and swapped them at the same time. The customer never brought the car back for the warning, and them appears to have sold it. Unless you just don't remember having the issue with your own car, but that doesn't seem to be the case. Ironically this appears to be the same diagnostic path you were going to take here. Speaking of lazy, who isn't familiar with their own service history?
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