What P0507 Means

Your engine is idling faster than the computer wants it to, and the computer can't pull it back down — plain and simple, too much air is getting into the engine with your foot off the gas.

Common Symptoms

• Idle sitting noticeably high — often a few hundred RPM above normal, sometimes over 1,500
• Check engine light on
• Idle that surges up and down, or "hangs" high when you let off the gas
• The car creeps harder at stoplights (automatics)
• A clunk or firm engagement when you shift into Drive or Reverse
• Slightly worse fuel mileage

The Most Likely Causes, in the Order I'd Actually Check Them

This is ranked the way I work through it in the shop — cheapest and most common first, not textbook order.

1. Vacuum leak. The number one cause of P0507, period. A cracked intake boot, a PCV hose that popped off, a brittle vacuum line, a leaking intake manifold gasket — any air that sneaks in without the computer metering it drives the idle up.
2. Dirty throttle body. Carbon builds up around the throttle plate. On electronic (drive-by-wire) throttles, that buildup costs the computer its fine control over idle air. A $10 can of cleaner handles it — but read the next item before you spray anything.
3. A relearn that never happened. If the battery was disconnected, or somebody cleaned or replaced the throttle body and skipped the idle relearn procedure, the computer's baseline is off. Nissans are famous for this — Altimas and Sentras especially. A skipped idle air volume relearn will set this code all day long.
4. Stuck or dirty IAC valve. On older cable-throttle vehicles, the idle air control valve gums up with carbon and can't close down the air passage like it should.
5. PCV valve or EVAP purge valve stuck open. A valve stuck open is just a vacuum leak the engine built for itself. Cheap parts, and easy to overlook.
6. The less common stuff. Throttle body or pedal position sensor faults, a poorly sealed aftermarket intake, and — rarely — the computer itself. Don't start here.

What I Check First in the Shop

First thing I do is pop the hood with the engine running and listen — a decent vacuum leak will hiss right at you. Then I pull up the freeze frame data to see what the engine was doing when the code set, and I ask the customer one question: has anybody touched this car lately? Battery swap, throttle body cleaning, intake work? More often than people expect, that question is the whole diagnosis — a relearn that never got done. If nothing's been touched, I smoke test the intake for leaks before I spend a dime of your money on parts.

Can You Keep Driving?

Honestly, yes — P0507 usually won't leave you stranded. But a high idle isn't free: you're burning extra gas, the transmission engages harder, and a car idling at 1,500+ RPM creeps hard in parking lots and drive-thrus, which is exactly how bumpers get dented. It can also mask other problems that come along later. Drive it to work this week? Fine. Ignore it for six months? I wouldn't.

Rough Cost: DIY vs. Shop

Broad, honest ballparks — parts prices swing a lot by vehicle:

• DIY: a vacuum hose costs a few bucks. Throttle body cleaner runs about $10. A PCV valve is usually $10–$30. An IAC valve often lands around $50–$150 in parts. Plenty of idle relearns cost nothing but your time — some are a pedal procedure, some need a scan tool, so look up yours.
• Shop: figure roughly an hour of diagnostic labor to start. A simple vacuum leak fix or a throttle body cleaning with relearn commonly runs somewhere in the $100–$300 range. An intake manifold gasket is a bigger job and can climb to several hundred depending on the engine. Anyone quoting you exact numbers without seeing the car is guessing.

Scan It Yourself Before the Shop Visit

Before you pay anyone for a diagnosis, pull the code yourself. My app, Auto AI Diagnostics, reads codes for free with any cheap Bluetooth OBD2 adapter — the $30 ELM327 or vLinker units work fine. AXEL, the AI in the app, doesn't just spit out a definition of P0507. It looks at your car's freeze-frame conditions — the RPM, temperature, and load at the moment the code set — and explains what's most likely going on with your vehicle, in plain English y en español. Walk into the shop already knowing what the code is and what questions to ask. It keeps everybody honest — including us.