Hello ALL,

I replaced the spark plugs on the 2017 F55S. Afterward, on acceleration, the stuttering and sputtering started. I got the danger drivetrain warno and the scanner showed P0301, cylinder 1 misfire. I double-checked the gap and torque, all in the green. What the heck?? I put new coil packs on today and I can drive around slowly, but when trying to accelerate, more of the same. The only things that I changed were the plugs and coil packs. No issues before the change. I've not had any problems in the past with a spark plug change on any auto, so I am kinda stumped. Thank you for any advice/help.
Edit: I did get a P0456 code 2 weeks before I changed the plugs.

 

P0456 is the fuel tank purge test failure code (tank has an air leak - google it). Most likely fault is the gas cap. Resolution: Remove cap, replace, run car, some number of restarts later (don't know how many), code should self reset. If code continues buy new cap. P0456 code is likely not related to the misfire.

Misfire: Quick and dirty takeaway from your description is that you M'ed something up during the sparkplug replace.

Go back: remove all "new" plugs, reinstall the old ones. Does misfire problem return? If Yes -> see mechanic; If No -> post pictures here of the new plugs that misfire.

Additional diagnostics: swap #1 & #2 coils and or plugs (I don't expect that to produce a useful finding) but you need to do it anyway to rule out the obvious. If misfire moves from #1 to #2 then coil or plug is bad.

More likely cause: You messed up or disconnected or did not properly reconnect something in the vicinity of the coils.

Hope that helps!

 

You helped very much. THANK YOU!

Update: switched the coil for cylinders 1&2, still the same. Then switched spark plug 1&2 and now the #2 cylinder misfires. I've never had a new, bad spark plug before. If this is happening to anyone else, try those steps and see if you have a bad, new spark plug.

 

Where do is you buy the spark plugs? Whether new plugs have been faulty in the past or not, it’s happening now. Get a new set of plugs from a reliable shop and try again.

 

New one for me, I cannot recall ever having a new-out-of-the-box plug defective, ever.

Suggest everyone do this search!: NGK counterfeit plugs

Best guess is the OP has a set of counterfeit plugs.

 

Yes. I would not purchase car parts on Amazon, unless it is a non-critical part, link sway bar end link or something like that. (even then, I would be wary) You can get genuine NGK spark plugs here - https://www.ngk.com/ Considering cost is relatively low, it's not worth it to me to save by shopping around for spark plugs.

 

OP, please let us know what your source for the plugs was.
Thanks

 

I bought them from Rock Auto. Bought many parts for various cars from there never any problems.

 

RockAuto is generally pretty good, but not flawless. I've received completely wrong parts from them in the past. I would still give consideration to a new set of spark plugs, especially since your troubleshooting narrowed it down to a faulty one..

 

Yep, check the fitment, I see overlap on those general parts sites, You pick an F56 and they show you r56 parts as they get data from Aies and Pies and its not right for MINI sometimes.

I know the newest part manufacture on MINI spark plugs is now Champion france. So they have gone to those as Genuine MINI branded parts.

https://www.northamericanmotoring.co...uine-mini.html

 

One bad spark plug replaced and we are back to 100%.

 

Excellent!