[Eric_M328i]

Hey guys so my 2008 328i has been stuttering at low rpms lately and after reading some posts iv concluded its the ignition coils and/or spark plugs. I also learned i can get ignition coils replaced for free with my SULEV warranty but the thing is my SA at BMW said the car needs to throw a code for them to replace it. So a while passed and finally tonight when i was pushing the car after getting my AA tune the car misfired and triggered a check engine light. I pulled over turned it off and on and the car was back to normal. Im most definitely sure this was the ignition coils that caused this but my question is, can spark plugs also trigger a SES or check engine light? Or is it just ignition coils that can trigger it. I dont have a obd2 scanner on me right now but i wanna get the car to my BMW center tomorrow to get the coils replaced asap finally and i wanted to make sure. Any inputs appreciated. Thank you!

[BimmerNugget]

Generally, if you have issues with coils or spark plugs, the car will throw a misfire code. It will tell you which cylinder the misfire is, but it won't tell you if it's the coil or plug. That's up for you to diagnosis.

All you have to do is swap the coils/plugs with a cylinder that is not misfiring and you know if it's the coil that's bad or the plug that's bad.

Also, how is the AA tune so far? Worth the $459 or not? Should I just save the $459 and drive in D/S mode all the time?

[Eric_M328i]

Originally Posted by BimmerNugget

Generally, if you have issues with coils or spark plugs, the car will throw a misfire code. It will tell you which cylinder the misfire is, but it won't tell you if it's the coil or plug. That's up for you to diagnosis.

All you have to do is swap the coils/plugs with a cylinder that is not misfiring and you know if it's the coil that's bad or the plug that's bad.

Also, how is the AA tune so far? Worth the $459 or not? Should I just save the $459 and drive in D/S mode all the time?

Oh i see. Cause iv read posts on coils goving SES lights but not plugs. Also the thing with my situation is i cant switch around plugs/coils constantly because this misfire took weeks to reappear.also i dont wanna deal with the the POS SA if its not the coils. Thank you tho.

So about the tune, honestly I really like it. DONT have very high expectations like the car will transform into something else but still. The throttle response is so much better and sportier and doesn't freeze up on you like it did before. Im pretty sure you know what im talking about. The shifts also feel a lot smoother and better. Now DS mode is just another monster. It feels so nice and smooth. And you can definitely feel some difference. Although the guy did say it takes 3 days for the ecu to adapt, an AA worker told me instantly. Well im testing that out rn but i instantly i felt a difference and it may even adapt better idk. ANYWAY I say go for it because eventually you're gonna want to do it. And it is worth it.