Slight misfire!


May 23, 2022
Hey SpoolStreet!

After going through hell with my 335i, I finally got it to a working state by re using the index 1 injectors but installing new Teflon seals and new decouplers along with a good 10min clean on each injector.

I've now got it to a state where it's running really nice under full WOT and pulls all the way to redline without any misfire, but, after doing a full WOT pull and when I come to a stop at the lights, it starts to misfire a lot... but the misfire will eventually go away after a minute on idle or rolling (Only happens after WOT or little aggressive acceleration)

Seeing if you guys might think it's a faulty coilpack or spark plug because I previously got cylinder 1 misfire code, so I swapped cyl 1's spark plug and coilpack with cyl 6 and now there's no codes coming up but it still misfires a little bit, wondering if it's coilpack and it's just not enough for it to throw a code... What do you guys think?

Don't have any log as I'm thinking it's just something simple as it's not a major misfire, you can just feel it dip on idle or at a slow pace after a WOT pull.

Cheers! :)


Nov 6, 2016
ACF 6466 E92 + METH

I would guess a leaking injector. But I am no expert and never had this issue. My buddy had something similar iirc and the new index 12 injectors fixed it. He had index 12s but they had over 125k miles on them and there was leaks in at least 1 bank if not both. FCPeuro really saved his ass as he bought them when they were cheap ;)

You can play around with swapping coilpacks and plugs etc. but I would just replace them all if you are unsure how long they have been on the car. For relatively small money and you can upgrade both the coilpacks and plugs at the same time to be better than what came from the factory.

Report back what fixes it for other people please to learn from your thread.

Best of luck!
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