Drivable short-term, but fix now to avoid damage.
P0521 means the engine oil pressure sensor or switch is reading out of its expected range. This could be a sensor or wiring fault, but it can also reflect a genuine oil pressure problem. Because low oil pressure can quickly ruin an engine, this code should be taken seriously and checked promptly.
$100 – $800
Varies by vehicle and root cause.
Be very careful. If it's just the sensor, the engine is fine, but if oil pressure is truly low, driving can cause severe engine damage. Verify real oil pressure first.
It ranges from about $100 for a sensor to $800 or more if the oil pump or related parts need attention.
It can be. While it's sometimes just a faulty sensor, it can also warn of a real oil pressure issue that threatens the engine, so don't ignore it.
A mechanic can attach a manual gauge to measure true oil pressure, which confirms whether the problem is the sensor or the engine itself.