When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi there I have a 2012 s550 with 85k miles on it, I purchased the car back in December of last year with no problems, when I got the car I had a full tune up, oil change, spark plugs, coil packs, and also filters. everything has been running smoothly until today, I had a check engine light on and I scanned for codes and I got this code P0301, it says it’s misfiring in cylinder 1. Is this something I can fix myself? I took it to the shop to see what they say. In the future are there things I can do to fix this on my own? I heard coil packs go out a lot on these cars.
When were the plugs last changed? You have to pop the air filter housings off, but on the 5.5 M273, swapping all 8 plugs and coils will take an hour with a stop for a wobble pop.
Can't speak for the later 4.7 turbo lump, but fundamentally it shouldn't be much harder.
Swap the affected coil for the one opposite. If the code moves then it's the coil, if it doesn't it's either the plug or the wiring.
Plugs, change all 8 at the same time. Always.
Coils, prudence would suggest changing all of them, but equally there's no shame in swapping them as they fail.
plugs and coil packs were all changed last December 2025
Genuine or aftermarket?
If genuine and a coil has failed, it should be warranted for at least 12 months if fitted by a certified shop. In which case start by taking it back there.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
Mercedes Teases Updated EQS With Steer-By-Wire and a Yoke
Slideshow: The 2027 update adds a fully digital steering system, revised styling, and potential charging upgrades as the company looks to revive interest in the luxury EV.
Slideshow: From problematic air suspensions to early dual-clutch transmission issues, these specific models and years stand out as the least dependable modern Mercedes vehicles.
P0301 Code?
