OBD-II Code P0507 — What It Means & How to Fix It

What Does This Error Mean?

P0507 means your engine's idle speed is higher than the computer expects. Normal idle is usually between 600 and 900 RPM depending on your vehicle. When idle RPM goes above the expected range, the computer sets this code. You'll notice the engine revving higher than normal when stopped at a light. The most common causes are vacuum leaks and a dirty throttle body.

Affected Models

All vehicles 1996+
Common in Honda Accord
Common in Nissan Altima
Common in Toyota Camry
Common in Chevrolet Malibu

Common Causes

Vacuum leak letting extra air into the engine and raising idle speed
Dirty throttle body with carbon buildup preventing proper closure
Failed idle air control valve stuck in the open position
Intake manifold gasket leak allowing unmetered air into the engine
Faulty throttle position sensor telling the computer the throttle is slightly open

How to Fix It

Clean the throttle body first — this is the most common fix. Remove the air intake duct to access the throttle plate. Spray throttle body cleaner on the plate and bore, then wipe clean with a lint-free rag.

Carbon buildup can hold the throttle plate slightly open, letting too much air in at idle.
Check for vacuum leaks. With the engine running, listen for hissing sounds around the intake manifold, vacuum hoses, PCV valve, and brake booster hose. Any leak lets extra air in.

Spray carb cleaner around vacuum connections while idling. If the RPM drops or changes, you found the leak.
Inspect the idle air control (IAC) valve if your vehicle has one. On older vehicles, this valve controls idle speed directly. Clean it with throttle body cleaner or replace it if it's stuck.

Not all vehicles have a separate IAC valve. Newer cars with electronic throttle control use the throttle body itself to control idle.
After cleaning or repairs, reset the idle by disconnecting the battery for 15 minutes. Then reconnect, start the engine, and let it idle for 10 minutes without touching the gas pedal.

This allows the engine computer to relearn the correct idle position. Some vehicles have a specific relearn procedure.
Check for any recently disconnected or reconnected vacuum hoses. If you or a mechanic recently did work on the engine, a forgotten vacuum hose is a very common oversight.

Take a photo of vacuum hose routing before any engine work — it makes reassembly much easier.

When to Call a Professional

If cleaning the throttle body and fixing vacuum leaks don't resolve the high idle, see a mechanic. Electronic throttle control issues and intake manifold leaks need professional tools. A mechanic can use a smoke machine to find hidden vacuum leaks. Expect to pay $80-$150 for diagnosis. Repairs range from $20 for a vacuum hose to $500+ for an intake manifold gasket.

Frequently Asked Questions

What is a normal idle RPM?

Most cars idle between 600 and 900 RPM when warmed up. During cold starts, idle may be higher — around 1,000-1,500 RPM. This is normal and should come down as the engine warms up. P0507 is set when the idle stays above the expected range. Check your tachometer — if it's consistently above 1,000 RPM when warm, that's too high.

Can a vacuum leak really make the engine idle high?

Yes, this is the most common cause of high idle. A vacuum leak lets extra air into the engine that the computer didn't expect. The computer can't reduce air flow below the amount leaking in. So the engine idles faster than it should. Even a small leak can raise idle speed by 200-400 RPM.

Is high idle dangerous?

It's not immediately dangerous, but it's annoying and wastes fuel. A high idle can also make the car creep forward more aggressively in drive. This makes parking lot driving feel jerky and harder to control. In extreme cases, the engine could overheat from running too fast. Get it fixed for comfort, safety, and fuel savings.