P0507: Idle Air Control System RPM Higher Than Expected
TL;DR
P0507 = idle RPM higher than expected. Severity: low. Top cause: vacuum / unmetered air leak (55%). Other causes: dirty/sticking throttle or IAC valve (30%), stuck PCV or faulty actuator (15%). Typical cost: $0–$80 (DIY) to $350 (at a shop).
Can I keep driving with P0507?
IF idle is only slightly high → you can drive short-term while you find the leak. IF idle is very high (e.g. revving well above normal) → be careful, as a high idle can make the car creep and lengthen stopping; fix it sooner. A vacuum leak can also cause lean codes.
Symptoms
- Check engine light on
- High or fast idle
- Engine revs higher than normal at stops
- Car may creep or feel like it wants to move
- Possible lean codes (e.g. P0171) alongside
Top causes (ranked by probability)
| Likely cause | Probability | Notes |
|---|---|---|
| Vacuum / unmetered air leak (hoses, gaskets, brake booster) | 55% | Most common — find and fix the leak |
| Dirty/sticking throttle body or IAC valve held open | 30% | |
| Stuck PCV valve or faulty throttle actuator/cable | 15% |
What does P0507 mean?
Technical explanation
P0507 sets when actual idle speed exceeds the commanded idle by more than the allowed amount. Because the ECM is already trying to reduce idle airflow, the usual cause is extra air entering downstream of the throttle that the system can’t fully compensate for — i.e. a vacuum leak (intake gasket, hose, brake booster, PCV). A dirty/sticking throttle plate or IAC valve held slightly open, or a sticking throttle cable, can also raise idle.
In simple terms
P0507 means your engine idles too fast. Most of the time that’s because air is sneaking in somewhere it shouldn’t — a cracked hose or leaky gasket — so the engine revs higher than the computer wants. Sometimes it’s a dirty throttle or a stuck valve. It’s usually a leak to track down.
How to diagnose P0507 (step by step)
- Read idle RPM vs target. Confirm actual idle is above the commanded value.
- Smoke-test for vacuum leaks. The most reliable way to find unmetered air — check intake gaskets, hoses and the brake booster.
- Inspect the throttle body and IAC valve. Carbon or a sticking plate/valve can hold idle high; clean as needed.
- Check the PCV system. A stuck-open PCV valve adds idle air.
- Relearn idle after repairs. Perform an idle/throttle relearn so the ECM re-centers idle.
Repair options & cost
- Repair the vacuum leak (hose, gasket, booster)
- Clean the throttle body / IAC valve
- Replace a stuck PCV valve
- Repair a sticking throttle cable or actuator and relearn idle
| DIY cost | $0–$120 |
|---|---|
| Workshop cost | $80–$350 |
| Repair time | 30 minutes to 2 hours depending on the leak |
Costs are local ballpark ranges and vary by region and vehicle.
Tools you’ll need
- OBD-II scanner (BlueDriver / ANCEL)
- Smoke machine / vacuum tester
- Throttle body cleaner
Vehicle-specific notes
- A vacuum leak is the most common cause and often shows up with lean codes like P0171/P0174.
- Check the brake booster and PCV hoses — easy-to-miss leak sources.
- Do an idle relearn after cleaning or replacing throttle/IAC parts.
Common mistakes to avoid
- Replacing the IAC/throttle body before finding the vacuum leak
- Overlooking the brake booster or PCV as a leak source
- Skipping the idle relearn
- Confusing P0507 (idle too high) with P0506 (idle too low)
Frequently asked questions
What causes a high idle / P0507?
Most often a vacuum (unmetered air) leak lets extra air into the engine. A dirty/sticking throttle or IAC valve, or a stuck PCV, can also raise idle.
Is P0507 dangerous?
It’s low severity, but a very high idle can make the car creep and affect braking feel, so fix it. It can also accompany lean codes from the same leak.
Why do I also have a lean code?
A vacuum leak that raises idle also leans the mixture, so P0507 often appears with codes like P0171. Fixing the leak usually clears both.
P0507 summary
| Meaning | Idle RPM higher than expected |
|---|---|
| Severity | Low |
| Safe to drive? | Caution — find the leak |
| Top cause | Vacuum / air leak (55%) |
| DIY cost | $0–$120 |
| Shop cost | $80–$350 |