Check engine lite
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2012 S550 4Matic
Check engine lite
I have 2012 S550 4Matic with 120K miles.The check engine light went on and my mechanic tells me it gives CAT code. Any idea about possible issues? The car drives absolutely fine, but gives a little vibration while standing in drive or in park position (not while in motion). I started doing my research so all ideas will be greatly appreciated. Thank you.
Thread Starter
Newbie
Joined: Jan 2023
Posts: 2
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2012 S550 4Matic
WDDNG9EB0CA486569 my mechanic tells me 420 or 430 codes. He doesn’t remember exactly.
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S500
Coil packs pop and throws a warning that it will damage the CAT (usually without putting EML on)
CPS goes, throws EML. but the symptoms is stalling and failure to start when hot
CAT sensors go pop with the heater circuit giving up...
you don't need Merc specific tools, but you should use diagnostic kit that gives the real code and description 420 and 430 is gibberish
CPS goes, throws EML. but the symptoms is stalling and failure to start when hot
CAT sensors go pop with the heater circuit giving up...
you don't need Merc specific tools, but you should use diagnostic kit that gives the real code and description 420 and 430 is gibberish
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Performance of the catalytic converter is monitored by comparing the signals between pre- and post-converter O2 sensors. If the signals don’t show that the converter works you get DTC saying you have converter problem when it very well could be an O2 sensor issue.
It it was my car I would get another post-converter sensor and taking turns replace the ones in the car and see if that helps.
Of course, it can be the converter issue but investing $200’ish in troubleshooting with a new O2 sensor makes sense when the other option is a several $k job.
It it was my car I would get another post-converter sensor and taking turns replace the ones in the car and see if that helps.
Of course, it can be the converter issue but investing $200’ish in troubleshooting with a new O2 sensor makes sense when the other option is a several $k job.
