P0507 on Chevrolet: How to Diagnose & Fix
Idle Air Control System RPM Higher Than Expected
1 Chevrolet model · 2 documented issues · $80-$500 repair
P0507 on Chevrolet by model: symptoms, diagnosis and fix
The 1.4L turbocharged Ecotec engine in the Sonic shares the notorious PCV system failure with the Chevrolet Cruze. The PCV regulator diaphragm integrated into the valve cover ruptures, causing massive vacuum leaks. Additionally, the intake manifold check valve (small red/orange valve) fails, compounding the issue. This affects virtually all 1.4T Sonics eventually, typically between 50,000-100,000 miles.
Common Symptoms
- Check engine light with P0171 (system too lean)
- Rough or unstable idle
- Excessive oil consumption between changes
- Hissing or whistling sound from engine area
- Poor acceleration and turbo boost loss
How to Fix
Replace the valve cover assembly (includes new PCV diaphragm) with the updated GM design. Replace the intake manifold check valve simultaneously. Inspect the corrugated PCV hose from intake manifold to turbo for cracks. Use only GM or quality aftermarket valve covers - cheap replacements fail quickly.
Sources for this issue (2)
On 1.8L Sonics the flexible intake duct between the airbox and throttle body is made of a nitrile/PVC blend that hardens with underhood heat and cracks in the accordion-shaped ribbed sections. Because the split is downstream of the mass airflow sensor, unmetered air enters the engine and the ECM sees a lean condition, setting P0171. The cracks are the classic hidden kind: with the duct installed and the ribs relaxed they close up and look fine, so shops frequently report 'no problem found' and owners chase O2 sensors and MAF cleaners for months. GM addressed it with a special coverage program on 2012-2014 Sonics and changed the replacement duct to EPDM rubber, which does not embrittle the same way. Sonic Owners Forum has a dedicated thread on the cracked intake being addressed by Chevrolet.
Common Symptoms
- Check engine light with a lean code
- Rough or hunting idle
- Hissing or sucking noise from the engine bay
- Hesitation on acceleration
- High positive long-term fuel trims
- Reduced fuel economy
How to Fix
Remove the duct from the car and flex and twist the ribbed sections while looking at them with a bright light - the splits open up under flex and are obvious once it is off the engine. Do not diagnose it in place. Replace with the updated EPDM duct rather than the original nitrile/PVC part. Also check for the other common lean-code source on this platform, a ruptured PCV diaphragm in the valve cover, then clear the code and verify fuel trims return to near zero at idle and cruise. If the car is within the special coverage window, the dealer may cover the part.
Sources for this issue (2)
P0507 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0507 mean on a Chevrolet?
P0507 stands for "Idle Air Control System RPM Higher Than Expected." This code means the engine is idling faster than the computer's target idle speed, typically by a set margin such as 200 RPM above commanded. The engine control module manages idle by metering a small amount of air around the throttle plate (via an idle air control valve or electronic throttle), and when it can't bring the RPM down to target it flags this code. The most common real cause is unmetered air sneaking into the intake — a vacuum leak — that the computer can't compensate for. It generally indicates extra air entering the engine or a problem with the idle/throttle control system. On Chevrolet it is documented across 1 model: Sonic.
What are the most common causes of P0507?
The most common causes of P0507 are: Vacuum or intake air leak (hoses, gaskets, intake boot), Dirty or sticking throttle body or throttle plate, Faulty or stuck idle air control valve, Leaking intake manifold or throttle body gasket, Stuck-open PCV valve or cracked PCV hose, Dirty mass airflow sensor giving false readings, Failing throttle position sensor, Leaking brake booster or its vacuum hose. The specific cause varies by vehicle.
How much does it cost to fix P0507 on a Chevrolet?
Published repair estimates on Chevrolet range from $80 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0507 on a different make?
View P0507 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.