P0507moderate severityGenerally driveable

P0507 Code: Idle Air Control System — RPM Higher Than Expected

Written in plain English and reviewed by the eli5cars editorial team · Last reviewed June 2026

What it means in plain English

When your engine is running at idle, it should sit at a steady speed — typically 600-800 RPM for most gasoline cars. The ECM controls idle speed by managing airflow through the throttle body (via an Idle Air Control valve or electronic throttle) and fuel delivery. P0507 means the actual idle RPM is significantly higher than the target — the engine is running too fast at a standstill. This feels like a racing or high idle, and it can cause rough gear engagement in automatics.

Most likely causes — ranked

#1 Vacuum leak (air entering the intake manifold past the throttle body)

most likely

Fix: A cracked intake boot, a disconnected vacuum hose, or a leaking intake manifold gasket allows unmetered air into the engine. The ECM cannot compensate, so the engine runs lean and the idle climbs. Spray carburetor cleaner carefully around intake seams, hose connections, and the throttle body gasket while the engine idles — if the RPM changes, you've found the leak. Fix by replacing the cracked hose or gasket.

DIY ~$15Shop ~$200

#2 Dirty or carbon-fouled throttle body

likely

Fix: Carbon deposits build up around the throttle plate, narrowing the bore and changing the airflow characteristics. When the ECM opens the throttle slightly for idle control, more air flows than expected due to the changed geometry. Cleaning the throttle body with a specialized throttle body cleaner and a lint-free cloth typically resolves this. Do not use carburetor cleaner on electronic throttle bodies — it damages the coating.

DIY ~$10Shop ~$100

throttle body repair guide

#3 Faulty Idle Air Control (IAC) valve

likely

Fix: On older vehicles with a separate IAC valve (not electronic throttle control), the IAC valve meters air bypassing the throttle plate to control idle speed. A stuck-open or electronically failed IAC valve passes too much air, raising the idle. Try cleaning the IAC valve with throttle body cleaner first. If the high idle persists, replacement is required.

DIY ~$40Shop ~$200

#4 Faulty mass air flow (MAF) sensor sending incorrect readings

possible

Fix: The MAF sensor measures incoming air volume so the ECM can calculate the correct fuel amount. A dirty or failing MAF sensor sends inaccurate data, causing the ECM to miscalculate idle targets. Try cleaning the MAF sensor with dedicated MAF sensor cleaner (never use carb cleaner — it damages the sensing wire). If cleaning doesn't help, replace the sensor.

DIY ~$50Shop ~$250

mass air flow sensor repair guide

Check engine light on? Get a free code scan

If your check engine light is on, most auto-parts stores (AutoZone, O'Reilly, Advance) will read the code for FREE — no purchase required, just walk in. Bring the code back here and look it up at eli5cars.com/obd2 for the plain-English explanation.

Note: a scan only helps when there's an active fault code. For purely mechanical symptoms (noises, vibrations, leaks), a scan may show nothing — the suspects listed above are your starting point.

Want to read the codes yourself?

First, the free option: AutoZone, O’Reilly, and Advance Auto Parts read your codes for free — no purchase needed. That’s the cheapest way to get the code to look up here. If you’d rather have your own so you can check anytime (and clear a code after a fix), the Veepeak OBDCheck BLE is an inexpensive, reliable plug-in reader that pairs with a free phone app and works on any car sold since 1996.

See the Veepeak OBD2 scanner on Amazon

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Frequently asked questions

Can I drive with P0507?

Yes, though a high idle can make the vehicle feel jerky when coming to a stop with an automatic transmission (the engine fights against the brakes). It's driveable but should be diagnosed within a few days — a vacuum leak left unaddressed can cause lean running conditions that stress the engine over time.

My idle is high only when cold — is that normal?

Cold fast idle (1,000-1,500 RPM) for the first 60-120 seconds after a cold start is completely normal — it's intentional and managed by the ECM. P0507 is set when idle is elevated beyond the expected range after the engine has warmed up. If the high idle only occurs when cold and settles down, it's likely normal warm-up behavior, not a P0507 condition.

How do I reset the idle after cleaning the throttle body?

On many modern vehicles with electronic throttle control (drive-by-wire), you need to perform a throttle body relearn after cleaning. The simplest method: disconnect the battery for 15 minutes, reconnect, and let the car idle untouched for 10 minutes to let the ECM relearn the throttle position. Consult your vehicle's service manual for the specific relearn procedure — some require a scan tool.

Where can I get P0507 scanned for free?

AutoZone, O'Reilly Auto Parts, and Advance Auto Parts all offer free OBD2 code scanning. They'll confirm P0507 and any related codes. Armed with the code, you can start with the no-cost checks: inspect all vacuum hoses for cracks and try a throttle body cleaning before spending money on parts.