Idle Air Control System RPM Higher Than Expected
In short
P0507 means your engine is idling higher than the computer commands — usually a few hundred RPM above the normal target. The most common real-world cause is unmetered air sneaking into the engine, typically from a vacuum leak or a dirty/sticking throttle body. The car is generally still drivable, but the high idle should be diagnosed and fixed before it gets worse.
Is it safe to drive with P0507?
In most cases it is safe to drive in the short term, since the engine still runs and the fault rarely leaves you stranded. However, a higher-than-normal idle can cause the car to creep at stops, increase fuel use, and add wear to the brakes and transmission, so don't ignore it. If idle is wildly high (1500+ RPM) or surging unpredictably, drive gently and get it checked promptly.
Symptoms
- Engine idles noticeably higher than normal (often 1000-1800 RPM at a warm stop)
- Car creeps forward at stoplights and requires firmer brake pressure to hold still
- Idle that hangs high after you lift off the throttle instead of settling quickly
- Reduced fuel economy from the elevated idle
- Check Engine Light on with code P0507 stored
- Occasional hissing or whistling sound from a vacuum leak under the hood
Common causes (most → least likely)
How to diagnose it (before buying parts)
- 1 Scan and record all stored codes, then note the actual idle RPM and the commanded/target idle RPM in live data to confirm how far off it really is.
- 2 Visually inspect all intake, PCV, and brake-booster vacuum hoses and the intake boot for cracks, loose clamps, or disconnected lines — the most common cause of P0507.
- 3 Perform a smoke test (or carefully spray a small amount of approved throttle/intake cleaner around suspect joints) to pinpoint any unmetered-air leak; a brief RPM change reveals the leak location.
- 4 Inspect the throttle body and throttle plate for carbon buildup, and check that the plate closes fully; clean only with throttle-body-safe cleaner if dirty.
- 5 If equipped with an IAC valve, test it for sticking or electrical faults; on electronic throttle bodies, perform the manufacturer's idle/throttle relearn procedure before condemning any part.
Repair options & cost
By manufacturer
Carbon buildup on the electronic throttle body is a frequent cause; after cleaning, an idle relearn (and sometimes a battery-disconnect reset) is needed or the high idle returns.
Aging PCV hoses and intake gaskets commonly develop vacuum leaks that drive idle up; the idle air control on older models can also stick from deposits.
Electronic throttle bodies often require a relearn/idle-air-volume reset after cleaning or battery service, and a missed relearn is a common reason P0507 persists.
Older port-injected engines with a separate IAC valve frequently set P0507 from a dirty or sticking IAC and throttle-bore carbon buildup.
Frequently asked questions
Can I drive with a P0507 code?
Yes, usually for the short term — the engine still runs and the car isn't likely to leave you stranded. But the high idle wastes fuel, makes the car creep at stops, and signals an underlying air leak or throttle issue, so have it diagnosed soon.
Will cleaning the throttle body fix P0507?
Often, yes, if carbon buildup is preventing the throttle plate from seating correctly. After cleaning you usually must perform an idle relearn procedure, or the computer may keep the idle high until it readapts.
What's the most common cause of P0507?
A vacuum leak letting unmetered air into the engine, or a dirty throttle body, are the two most common causes. Both raise idle above the commanded RPM and are relatively inexpensive to fix.
How much does it cost to fix P0507?
Many fixes are cheap — a vacuum hose or throttle-body cleaning often runs under $100 DIY. If an IAC valve or electronic throttle body must be replaced, shop costs typically range from about $150 to $650 depending on the part and labor.