V Klasse engine power loss after tuning

I had a comparable situation with my V Klasse. The error codes pointed towards issues arising from aftermarket modifications affecting the car computer's parameters. Can you specify the diagnostic code you retrieved? This will help determine the specific nature of the fault.

The diagnostic code is P0299, indicating a turbocharger underboost condition. Does this match your experience? Were there any other symptoms besides the reduced power and dashboard light?

Yes, P0299 aligns with my experience. Given that the issue arose post-tuning, I would advise seeking assistance from a qualified workshop familiar with Mercedes vehicles and aftermarket modifications. They will have the necessary tools and expertise to properly diagnose and rectify the problem, potentially involving a recalibration of the car computer or hardware adjustments.

Thank you for the advice. I took it to a workshop specializing in Mercedes. They confirmed the chip tuning was indeed the source of the problem. They were able to rectify the issue with a software adjustment. The repair cost 180€. Appreciate your help.