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Help I just changed new spark plugs and I get these codes
I just recently did my spark plugs and coil packs . After a while of driving I started getting these codes . I don’t know what I did wrong? Is it bad spark plugs? I don’t see an issue .
How does the car run? I would think it would be misfiring and stumbling with those codes.
Are the codes STORED or CURRENT? Have you tried clearing them? Disconnecting the coils to remove them could have caused this.
What plugs did you use?
it says stored I believe . I clear them , they go away and my car runs smoother . But when light comes on , it starts stumbling a little bit not much but a little. Disconnecting the coils? What do you mean?
it says stored I believe . I clear them , they go away and my car runs smoother . But when light comes on , it starts stumbling a little bit not much but a little. Disconnecting the coils? What do you mean?
You put counterfeit coils and counterfeit plugs. Not sure further diagnosis is needed.
Fit OE plugs, refit original coil packs. It's a really bad idea to fit Chinese knock off parts, which these look like.
Out of interest, why did you replace the original coil packs?
Fit OE plugs, refit original coil packs. It's a really bad idea to fit Chinese knock off parts, which these look like.
Out of interest, why did you replace the original coil packs?
I believe the OE/Mercedes coils in my M272 engine are made by Delphi.
From experience I personally would only use Genuine MB or Delphi replacements. On FCP the Delphi coils have positive reviews.
I plan on replacing the spark plugs in mine and will be ordering the Genuine Mercedes plugs. My Operators manual states use non-resistor Bosch Y 7 MPP33 and when I contacted FCP they claim the Genuine Mercedes plugs they stock are in fact the Y 7 MPP33 plugs. I see people use the Bosch YR7MPP33 plugs with no issues also.
Back to ignition coils. I dont see them being wear items, out of all my previous cars I have only had to replace 1 ignition coil and I have had some high mileage cars. I wouldnt just replace them unless there was an issue with them. If it was listed on the maintenance manual based on years/mileage then I would follow what it says.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Gkbrans
Disconnecting the coils? What do you mean?
You need to unplug the wiring harness and remove the coil in order to access the spark plug.
You should not use aftermarket parts for key components. A-Premium makes pretty good stuff, but I wouldn't use them or any other aftermarket stuff for things for the engine. FCP Euro, Pelican Parts, AutohausAZ, and others list only quality stuff, and then you can still have problems if the part is not Genuine or OE. Mercedes tend to be very temperamental when it comes to parts.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by cvx5832
You put counterfeit coils and counterfeit plugs. Not sure further diagnosis is needed.
They're not counterfeit parts, just not genuine. If they claim to be Mercedes labeled parts, then that would be counterfeit. And there are plenty of those.
They're not counterfeit parts, just not genuine. If they claim to be Mercedes labeled parts, then that would be counterfeit. And there are plenty of those.
When the parts in question don’t have branding on the part, production markings or part numbers, they’re probably counterfeit.
When the parts in question don’t have branding on the part, production markings or part numbers, they’re probably counterfeit.
Parts can only be termed counterfeit if they claim to be OE and are not, use branding without permission, and/or break intellectual property rights. Coil packs (like spark plugs) are non proprietary.
Quality is the only real concern here. Delphi coil packs are readily available and much cheaper than Mercedes branded ones.
Fit OE plugs, refit original coil packs. It's a really bad idea to fit Chinese knock off parts, which these look like.
Out of interest, why did you replace the original coil packs?
I changed them because I just got this car 4 months ago and realized I didn’t know when the previous owner did spark plug change. It was about that time to change spark plugs as instructed on manual . I thought might as well change the coil packs while I’m changing sparks ?
I believe the OE/Mercedes coils in my M272 engine are made by Delphi.
From experience I personally would only use Genuine MB or Delphi replacements. On FCP the Delphi coils have positive reviews.
I plan on replacing the spark plugs in mine and will be ordering the Genuine Mercedes plugs. My Operators manual states use non-resistor Bosch Y 7 MPP33 and when I contacted FCP they claim the Genuine Mercedes plugs they stock are in fact the Y 7 MPP33 plugs. I see people use the Bosch YR7MPP33 plugs with no issues also.
Back to ignition coils. I dont see them being wear items, out of all my previous cars I have only had to replace 1 ignition coil and I have had some high mileage cars. I wouldnt just replace them unless there was an issue with them. If it was listed on the maintenance manual based on years/mileage then I would follow what it says.
I changed my coil packs to the previous ones I had . Hopefully I won’t get the check engine light . Spark plugs should be fine right? I’ll look into the options you laid out for me . Thank you
I changed them because I just got this car 4 months ago and realized I didn’t know when the previous owner did spark plug change. It was about that time to change spark plugs as instructed on manual . I thought might as well change the coil packs while I’m changing sparks ?
Nope. Unless you have picked up on a diagnostic code, or experiencing a misfire, there is no need to change the coil packs. Companies market plug and coil pack kits, because they know that folks will adopt a "might as well" approach. Great for business!
A coil pack plays a critical and highly stressed role, and a new "off brand" component could perform less effectively than the OE version that it replaced. There are also the horror stories of cheap Chinese coil packs spontaneously combusting. High currents and voltages are involved.
I would refit the original coil packs, and if any of these are actually faulty, then replace with OE branded or Delphi.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Gkbrans
I changed my coil packs to the previous ones I had . Hopefully I won’t get the check engine light . Spark plugs should be fine right? I’ll look into the options you laid out for me . Thank you
The M272 is port injection, so indexing the plugs is not critical. HOWEVER, you do need to torque to spec. No doing it by "feel" or the instructions on the box. Also, go with Bosch or NGK or Genuine. (Bosch vs. NGK is whatever the original plugs were.)
Last edited by JettaRed; May 13, 2025 at 09:50 AM.
The Chinese excel at making products to achieve a target cost. There are high quality Chinese products and there is also junk. You truly do get what you pay for when you buy "Made in China".
Im not that familair with the A-Premium brand but I see the parts being sold on places like Amazon. I dont think they are anything like a scam company, they seem to just be selling replacement parts for a low price. Can read the reviews, they seem typical for any aftermarket parts place. Some people like them, some have negative reviews.
I would not use those coils or plugs. If you can try to return them for a refund for not working. You are clearly getting fault codes with them so they arent working properly. Gather all the photos and documentation of the faults, check engine light on etc and file a return claim. I would send everything back even the plugs. Basically you cant use the coils and you spent a good amount of money on them.
For parts try to only use Genuine Mercedes or whoever made that specific part you are replacing. The Dephi coils are a good example. Things like air filters, the Genuine Mercedes are made by Mann in the M272 engine.
For things like oil, coolant, transmission fluid, brake fluid make sure it meets the Mercedes BEVO specs. Can find them all here: https://operatingfluids.mercedes-benz.com/
Along with the Operators Manual in the glove box there should be a Maintenance manual. This has all the recommended maintenance based on mileage/years. When I got my W204 i went through it and made sure everything was up to date. Its really not alot of work, most is just saying to inspect things.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
This part should be kept in mind. Most people will toss the packaging, etc. after installation.
I have bought a couple of A-Premium parts for my 21 year old Audi, namely the rear springs and shocks. The car doesn't get driven a lot, so I didn't want to spend a ton of money on the parts. So far, they have held up well. When looking at prices, the A-Premium parts are not the cheapest.
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