Drive with caution — fix soon.
P0506 means the engine's idle speed is lower than the computer expects. This is usually caused by something restricting airflow at idle, like a dirty throttle body, a vacuum leak, or a faulty idle air control valve. It can make the engine feel like it wants to stall when stopped.
$100 – $450
Varies by vehicle and root cause.
Usually yes, but the engine may stall at stops, which can be inconvenient or unsafe in traffic. Get it checked before it worsens.
Often $100 to $450. A throttle body cleaning is cheap, while replacing an idle air control valve costs a bit more.
It's moderate. The biggest concern is stalling at idle, but it doesn't usually cause lasting engine damage if fixed reasonably soon.
Yes, very commonly. Carbon buildup restricts the small amount of air the engine needs at idle, dropping the RPM below target.