CEL after plug change
Thread Starter
Junior Member
Joined: Mar 2021
Posts: 36
Likes: 9
2019 Cadillac CTS
CEL after plug change
I just finished changing my plugs and air filters on my '12 S5504V and I've got a CEL. I did rip a coil boot and I had to replace it, but otherwise, everything went without a hitch. I'll run it over to the dealer but I thought I'd see if you guys had any ideas.
Thread Starter
Junior Member
Joined: Mar 2021
Posts: 36
Likes: 9
2019 Cadillac CTS
I was trying to figure out how to read it on the display but remembered I have a cheap OBD2 reader. Hooked that up and got a code for a misfire, didn't write down the code because I had to start the car with only 7 coils so I wasn't surprised. Cleared it and we'll see what happens I guess.
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
2012 is already the direct injection engine, right? This engine should use the indexed spark plugs that have the electrode pointing in the correct direction after tightening.
Were your spark plugs the correct indexed type?
Were your spark plugs the correct indexed type?
Thread Starter
Junior Member
Joined: Mar 2021
Posts: 36
Likes: 9
2019 Cadillac CTS
Cleared the code and it drives and runs perfectly, code hasn't come back yet either.
As far as indexing, that's the first I've heard of that being necessary on my car, so no they're not indexed.
As far as indexing, that's the first I've heard of that being necessary on my car, so no they're not indexed.
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
I'm not sure when the DI engines came but I have read in this forum about the plugs needing to be indexed with DI engines...
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Joined: Sep 2019
Posts: 623
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From: My house
SL55AMG, GL450, SLK, S550, Maserati Coupe
If your code doesn't come back and the car runs well, you're golden.
I would only bring one of my Mercedes to a Mercedes dealership if it was on fire. I use a local shop that's family owned over 30 years specializing in Mercedes so I am lucky. They have a couple guys on staff who are former dealership techs and do things right, without stealing from my car like the local MB dealership have done. I also have a indy guy who is pretty good.
I would only bring one of my Mercedes to a Mercedes dealership if it was on fire. I use a local shop that's family owned over 30 years specializing in Mercedes so I am lucky. They have a couple guys on staff who are former dealership techs and do things right, without stealing from my car like the local MB dealership have done. I also have a indy guy who is pretty good.
Last edited by tonylinc; Jun 5, 2021 at 12:33 PM.
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Super Member
Joined: May 2019
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From: Omaha, NE
2007 S600
Really, though…. I’ve had mine to the dealer once. The SA was great; she tried her best to get my ABS/ESP control module replaced under warranty, but it was just too far past the coverage. The tech was a little more disparaging toward my car, I’m sure they don’t see many W221s there. Overall I was satisfied with the work they did, I just haven’t been back because most everything that the car has needed I could do without paying $160 per hour. You need deep pockets, or a lot of time and knowledge to keep one of these running — especially if the PO neglected to properly maintain it.
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From: Fleriduh
W212 E63S Wagon - GSL580 - E63 - E350 - C300
I had my Benz comptuer in the car and read the code about 30 seconds later....so, certain on the code (did not write it down cause it was seeminly a one off).
Car is a '14 with >40k...going to order plugs and coils just to be sure. Heck, eight is not bad, my C240 takes 12!
And no, the Honda did not "beat me" - LOL
Car is a '14 with >40k...going to order plugs and coils just to be sure. Heck, eight is not bad, my C240 takes 12!
And no, the Honda did not "beat me" - LOL
