E Klasse check engine light and idle issues

The check engine light coming on along with idle problems could definitely be related to the air intake system. Does the engine hesitate during acceleration, or feel sluggish I had a similar issue with my E Klasse and it turned out to be a defective hose connection from the pump to the valve. Did you already check the hose connections for any cracks or leaks What diagnostic codes are you getting

Defective hose connection, you say Where exactly is this hose located And what kind of diagnostic codes were you seeing Any chance you remember

Yes, the hose runs from the secondary air injection pump to the air switching valve. If you're not familiar with the system, it's probably best to take it to a workshop. I was getting codes related to secondary air injection system inefficiency. To be sure, the repair cost me around 175€. I know it's annoying, but it's better than causing more damage by messing with it yourself.

Thanks a bunch Took it to the shop and you were spot on. Hose connection from pump to valve was indeed the culprit. 175€ later, the check engine light is gone and it runs like new. Appreciate the help