[Pearly92]

Changed bmw spark plugs 1 step colder now car idles funny and I got one code. Not sure if I gapped Inproperly or if I did something else wrong. It’s gapped at 23 and I put everything back in order and when I go to start it turns on but after a second or two it idles rough like a vibration. I checked for codes and I’ve only got one.

29D0 - Intake air temperature sensor, electrical: Short circuit to B+.

Not sure what it is I’m stage 2 mhd

[wheela]

Maybe you bumped the wiring to one of your tmap sensors? I'm not sure if "intake air temperature" refers to the chargepipe tmap, the manifold tmap, or either/or. But I'd check wiring and connections for both of those to start.

[TheGoodTheBadTheUgly]

From experience this code pops up when you remove the air intake system to do maintenance or you run the car with no MAF for a few seconds.

Check to insure your MAF is plugged in correctly or didn't get dirty and that all the ducting is back in properly. It should rough idle for a few seconds to a minute if MAF was left unplugged while running, up until it recalculates appropriate fueling for the actual intaked air.

[Pearly92]

I started the car with everything back on and the wiring looks fine not sure what else could gone wrong.

[whyzee125]

Try running the stock Bosch plugs again, no need for colder plugs on MHD stage 2

[Pearly92]

I changed to ngk 97506 1 step colder recommend for n55. There could be a possibility I gapped it wrong but I doubt it.

[TheGoodTheBadTheUgly]

Originally Posted by Pearly92

I started the car with everything back on and the wiring looks fine not sure what else could gone wrong.

That code comes on when the MAF is disconnected and reconnected while the battery is still connected. The car knows that the MAF sensor has been unplugged and that the circuit is opened so it throws this code.

This being said, it should disapear after a few minutes when you let the engine run or by clearing it. The engine is also expected to run a bit rough maybe but then it should stabilize. How long did you let the engine run and it was still acting as rough idle?

Also are you stock air intake system? My BMS air intake tended to throw this code a lot when I would play around with it.

I don't think it's the spark plugs caused that code but you could still be misfiring which is maybe what you are discribing.

[Pearly92]

Yes I’m still on the stock intake it starts up and vibrates and makes a sound which lowkey scares me 😂. Do you have any social media or an app where I can send you the videos of the car?

[Pearly92]

Here’s the post I put on Reddit this has a video reddit spark plugs

[TheGoodTheBadTheUgly]

Originally Posted by Pearly92

Here’s the post I put on Reddit this has a video reddit spark plugs

Ahhhh that seems to me like misfiring. I remember near the end of winters sometimes I had a plug that would do this when I would startup the car but it was too cold for me to change them so I would continuously clear the codes until it stabilizes just so I could make it to better weather.

Ensure all your ignition coils are connected well and as it was suggested, try to swap back to the OE Bosch plugs to ensure it's not a gap or manufacturing issue with the NGK.

[wheela]

I know Google says 29d0 is cylinder 4 misfire, but his screen shot says electrical short on his intake air sensor. Check out the attached list of n55 codes I have, it aligns with OP's screenshot (just use search function for 29d0). Here are some screenshots of what it says to check for regarding this code.

I believe this points to the tmap or tmap wiring? (tmap = temperature & manifold absolute pressure)

[HMan04]

Hey man! A friend of mine that works at the BMW speed shop here in Nashville was having the same issue, it seems one of your spark plugs is faulty causing a misfire. Also have your fuel injectors checked in turn as well, it may be time for them to be replaced, depending on the mileage and use however intense of the car. It may not read it on your code reader, the BMW spec’d ones the dealership uses however will show it.

Cheers! Much love!

[Pearly92]

UPDATE, hey guys I decided to take out all the spark plugs again and double check the gap seems like I gapped cylinder 4 and 5 incorrectly now it doesn’t misfire. Thanks for the help guys! I still have the codes but I’m going to clear them after I put everything back.

[wheela]

Originally Posted by Pearly92

UPDATE, hey guys I decided to take out all the spark plugs again and double check the gap seems like I gapped cylinder 4 and 5 incorrectly now it doesn’t misfire. Thanks for the help guys! I still have the codes but I’m going to clear them after I put everything back.

Nice! What gap were they at, and what did you correct to? I'm currently on stock plugs/gap, but have some 97506's that will be going in eventually.

I wonder why the code references the temp sensor if it's a cylinder misfire on #4

[Pearly92]

So cyl 4 was gapped too big it was at like 30 I either forgot to gap it thinking I already did it or I just forgot like an idiot I just took it out and gapped it to 23. Next cyl 5 was too closed it was at like 20 damn near touching the tip I went ahead opened the gap a bit more then put it at 23 as well. That fixed my issue the car runs great just did a test run. As for the codes I just cleared them and ill be checking for them later to see if they’re still there.

[TheGoodTheBadTheUgly]

Nice! That defenetly sounded like misfiring, now at least you know what it sounds like. Only thing missing is for you to feel a misfire while doing a pull but trust me you will probably infer what is it lol.

It's a good thing to have upgraded plus but really not necessary for stage 2+. Really becomes mendatory when you are upgrading turbos andnwill havd more agressive tuning and generating more boost.

So if ever you are having misfiring issue with those and need to order some, you can just swap in the stock Bosch meanwhile.