Hi everyone,

I have a 2014 Clubman S with 81k miles that I bought it about 6 months ago. The engine has a Stage 1 Manic tune, spark plugs changed at 60k.

Last night as I was accelerating hard, the engine stuttered where it felt almost like a vibration from a driveshaft, and it went away as I let off. Over the next 5 miles, it go worse and worse and I believe its misfiring. It idles roughly on start at about 1000 rpm.

I put my Maxiscan on it today and got an P 0304 misfire on Cylinder 4. I swapped the coils between 3 & 4 and then got a series of codes:

• 0303
• p0300 p
• p0304 p
• p0303 p

Then I cleared the codes and it is still idling rough on start, but hasn't set a new code. I can drive it a bit and see, but I wanted to get some advice on things to check. I am not sure why the OBD code isn't getting set after I cleared it, but maybe that just takes a certain amount of time?

-Pull & inspect the spark plug in #4
-other things to check?

I've never troubleshooted ignition issues, so I'm a novice and thanks in advance.
MJ

 

You should be running NGK 1422 plugs, if you’re not already. If it is truly a misfiring situation, I would immediately replace plugs and coils. Make sure you get good quality coils, not cheap aftermarket ones.

 

Thanks, I have a set of 1422s on the shelf, I'll replace those and coils and hope that fixes it. What should they be gapped to do you know by chance for the tune?

The current plugs are Beru, 12 zr-6spp2-1

 

I have my 1422’s at the “out of the box” gap, and no problems

 

perfect, I saw Mario say .024, which is a little wider than out of the box, but all good. New plug and new coil=problem solved. Thanks so much! I went ahead and ordered 4 new coils but the quick check with the cheap one was golden. Thanks again!