a6itv

Hey guys, (posted in w218 cls63 forum, posted here for more views)
I have a 2015 cls63 (m157) , sits at 46k miles right now. I had a ecc slav stage 1 ecu/tcu tune (tuned it at 42,100 miles) and the tune ran beautifully, no issues, no codes, etc. I tuned back to stock a week ago to pass smog since I live in CA, and the car began misifiring a few days later at low rpms. I was in 5th gear going around 60 mph, not much load on the engine at all and the CEL came on, started flashing at me. Pulled over, turned engine on, off, waited a minute, turned it on and plugged in my scanner and it says p0357, p0300, p13c5 (misfire, low voltage coil codes).
I did spark plugs around 38k miles so I doubt it is those, injectors seem fine too since it's not running rich either. I'm replacing all ignition coil packs this weekend, any thoughts on what this may be? The car WAS tuned for 4k> miles, currently it is running stock tune.

Chevota

Mine did that ~the same mileage. It was a bad coil. I think they designed them to fail just after warranty, but clearly it wasn't perfect.
Mine would miss here and there at light loads, then over time more often and over a broader range of loads. Very annoying... You can replace the one and wait for the others to go one at a time, or do them all now.
I don't know if there are any coils for it not designed to fail, so I can't suggest a brand.

Mojo20032004

Check the wiring for oil, make sure the pigtails are not wet from oil

PeterUbers

coils will fix this - easy fix and fun little job. Car will run better than ever after coils with stock or tuned ecu; beru coils are more robust build and ideal

check the sticky - lots on misfires and coils
https://mbworld.org/forums/w212-amg/...2-amg-e63.html

PeterUbers

always a wise recommendation

https://mbworld.org/forums/w212-amg/...sors-leak.html

a6itv

Will let you know Sunday when I get my coils in lol. I'll reset codes and see if it messes it up again

a6itv

Hope it's not this. Could be a head gasket then

Mojo20032004

No not headgasket, but leaking cam sensors or cam magnets causing oil to wick into harness, it can make it's way to other parts of the engine to cause shorts and havoc. Tasos posted a video of a g wagon m157 engine that has these issues. Very common and known issue across the entire mb lineup

PeterUbers

it's just your coils

Consider reading the sticky topics - lots to learn

a6itv

Did all 8 new coils. Yesterday it was cylinder 7, today it's cylinder 2 and 4 lol. Getting new coils and re installing tomorrow.

PeterUbers

recent new gas station? Did you have an E Tune?
is there oil in the wire harness?
are the plugs indexed appropriately?
have you thrown the tuned ecu back in - do the CEL's go away?

a6itv

Cylinder 2 and 4 coils were bad... got new coil packs for those cylinders and car runs great now (only drove it 20 miles with new coils, but I pushed it lol).

Coil packs were the issue I guess. Will update if it goes wrong again

PeterUbers

yep.