Aygo oil pressure light and temperature sensor issue

That sounds plausible. Is the engine oil temperature sensor error code specified when reading the error memory? A faulty sensor or its wiring could cause those symptoms.

I don't have the specific error code, but if the cable or plug connection of the sensor is defective, would that cause the oil pressure light to come on as well?

Yes, a defective cable or plug connection on the temperature sensor could certainly lead to the oil pressure warning light illuminating. It's all interconnected. I'd recommend a workshop visit.

Thanks for the advice! It turned out the temperature sensor cable was faulty, just as you suspected. Repair cost me 95€, and the problem is resolved.