michakaveli, venting the crankcase to the atmosphere will not cause a check engine light. That's not something that the computer monitors. Just look for a hose going from the valve cover to somewhere in the intake.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References