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GLC hybrid mixture preparation error

My 2018 Mercedes GLC hybrid is throwing a mixture preparation error. It's got about 201456 km on the clock. The usual symptoms are there: reduced engine power, check engine light, rough running, jerking when accelerating, and occasionally stalling at idle. I've scanned the codes and it's pointing towards a possible defective injection valve or injector. Could a faulty oxygen sensor cause a rich mixture and trigger this? I am also concerned about the catalytic converter since I know a bad air-fuel ratio could damage it. I even considered spark plugs, but I don't think they would cause such a severe issue. Any thoughts before I start replacing parts?

4 comment(s)

I had a similar issue with my GLC. The symptoms you describe sound very familiar. Did you notice any changes in fuel consumption? Have you checked the air-fuel ratio at all? My problem turned out to be related to the injectors, but I would suggest you to check all related components before you make a decision.

Thanks for the quick reply. Fuel consumption seems a bit higher than usual, yes. How did you pinpoint the injectors? And do you remember what the air-fuel ratio was when you checked? I'm trying to avoid replacing unnecessary parts, as you can imagine.

I did not check the air-fuel ratio. I brought my car to a workshop because I did not want to deal with the problem myself. I would suggest you do the same.

Appreciate the advice! Took it to a workshop and they confirmed it was indeed a faulty injector. Repair cost me 515€. Running smoothly now. Thanks again!

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