Mercedes GT Roadster Hybrid power loss after tuning

Whoa, chip tuning on a hybrid GT Roadster? Bold move! First, ditch the generic auto scanner and get a proper car diagnostic done. What fault code exactly did you pull? And are you absolutely sure about the chip tuning? 'Cause that'll void your warranty faster than you can say 'check engine'

The fault code is P0299, indicating a turbocharger underboost condition. I am reasonably certain about the chip tuning; the previous owner disclosed it. Regarding the car diagnostic, are there specific parameters I should monitor beyond the standard sensor readings?

P0299 with aftermarket tuning? Yeah, that's screaming 'overboost gone wrong'. The car's ECU is probably fighting the tune. Monitoring fuel trims and boost pressure would be wise, but honestly, you're poking around a potential minefield. Best bet is to take it to a reputable workshop who knows these cars inside and out. They can properly diagnose if it's just the tune or if it's cooked something else

I appreciate the insight. I followed your advice and consulted a specialist. The faulty chip tuning was indeed the issue. The cost to remove and revert to the original ECU settings was 180€. Thank you for confirming my suspicions and pointing me in the right direction