4990: Exhaust backpressure sensor before turbocharger, plausibility
4990: Exhaust backpressure sensor before turbocharger, plausibility:
This tricky due to poor translations from scanner to scanner, it can mean EGT #1 is unplugged/not working
or
Exhaust Manifold pressure sensor has an issue, meaning the sensor hose can be damaged (super common)
https://www.tunemyeuro.com/bmw-manifold-pressure-sensor-hose-13627812806/
or
pressure sensor is damaged (needs adaptations reset with ISTA)
https://www.tunemyeuro.com/bmw-m57-exhaust-pressure-sensor/
in rare cases, MAP sensor is damaged, usually the car will have strange RPM actions, key give away. May also require exhaust manifold pressure sensor adaptation reset
https://www.tunemyeuro.com/bmw-pressure-sensor-map-sensor-13-62-7-792-260/