Rough idle and check engine light turned on

2008 MERCEDES BENZ C350
88,000 MILES • 3.5L • 6 CYL • 2WD • AUTOMATIC
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RON LEHAN
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The car runs perfectly - started and idled rough. Drove around the block and idled cleaned up but service engine light came on.
Feb 7, 2022 at 2:43 AM
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SQM
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Hello,

Rough idle can be due to a number of reasons. It could be for a vacuum leak, misfire, issue with the mass air flow sensor, fuel issue etc. The check engine light gets triggered when the on-board diagnostics detects any faulty within the engine management systems.

Since the check engine light is illuminated, the best course of action would be to scan and retrieve the trouble code(s). If you do not have a scanner, you can take it to your local auto parts store, and they will scan and provide you with the codes.
Knowing the code can help narrow down the possible cause.

Here is a helpful guide:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let me know what code(s) you are able to find.
Thank you.
Feb 7, 2022 at 6:58 AM