Arkana check engine light and power loss

I own a Renault Arkana as well and I had similar symptoms. It turned out to be a defect in one of the camshaft solenoid valves, causing the variable timing to malfunction. Have you checked the power supply to the valves? It may also be the issue.

How did you determine that the camshaft solenoid valves were the issue? Did you perform any specific tests or diagnostics to pinpoint the problem?

The error codes pointed to the inlet camshaft. Given the mileage, and the symptoms you described, it's highly probable that your VANOS is failing. I would recommend taking it to a workshop for a proper diagnosis. It could be a defective valve or something else entirely.

I took it to a local mechanic, and after checking, it was indeed a defective inlet camshaft solenoid valve. The repair cost was around 250€, exactly as I feared. I appreciate your help in pointing me in the right direction.