P158b Renault !!better!!

With the engine off, disconnect the vacuum hose from the turbo actuator. Attach a hand vacuum pump. Apply vacuum (about 250-300 mmHg). Watch the actuator rod. Does it move smoothly and hold vacuum? If it leaks down or moves roughly, the actuator diaphragm is torn or the VGT mechanism is sticking.

To resolve the P158B code, a systematic approach is necessary: p158b renault

Diagnosing the P158B code requires a systematic approach to check both the component and the wiring. With the engine off, disconnect the vacuum hose