Medium Severity — Powertrain OBD-II DTC

P0146: Fuel and Air Metering (Injector Circuit) Malfunction (P0146)

P0146 is a generic (SAE standard) powertrain diagnostic trouble code (DTC) indicating: Fuel and Air Metering (Injector Circuit) Malfunction (P0146). This code is set when the vehicle's onboard computer (ECM/PCM) detects a fault in the fuel and air metering (injector circuit) system.

⚡ Quick Summary

Severity

Medium

DIY Level

Moderate

Repair Cost

$80–$300

Urgency

Fix within weeks

🚨 Symptoms of P0146

▸ Check engine light on

▸ Misfire on specific cylinder

▸ Rough idle

▸ Reduced power and fuel economy

🔍 Common Causes of P0146

HIGH

Faulty fuel and air metering (injector circuit) component

MED

Wiring issue — open, short, or corroded connector

LOW

ECM/PCM software issue or internal failure

🛠️ How to Fix P0146

⭐ Most Common Fix

Diagnose and repair fuel and air metering (injector circuit) circuit

💰 $80–$300 🔧 Moderate

Repair or replace damaged wiring/connectors

💰 $50–$200 🔧 Easy

Replace faulty fuel and air metering (injector circuit) component

💰 $150–$500 🔧 Moderate

🔬 Step-by-Step Diagnosis

1 Measure injector resistance with a multimeter — compare to spec (typically 12-16 ohms)
2 Check injector connector for corrosion, damage, or loose pins
3 Swap the suspect injector with an adjacent cylinder to confirm the fault moves
4 Inspect the injector wiring harness for chafing or breaks

⚠️ Common Mistakes to Avoid

✗ Replacing the injector without testing the wiring first
✗ Not checking for fuel contamination or clogged injector
✗ Ignoring a misfire code that accompanies the injector circuit code

💡 Pro Tips

★ Always check for Technical Service Bulletins (TSBs) for your specific vehicle — manufacturers often release updated repair procedures for common P0146 issues.
★ Before replacing expensive parts, verify power, ground, and signal at the component connector with a multimeter.

❓ Frequently Asked Questions

What does P0146 mean? ▾

P0146 means Fuel and Air Metering (Injector Circuit) Malfunction (P0146). The vehicle's computer has detected a fault in this system that needs diagnosis.

Can I drive with code P0146? ▾

This is a moderate issue. You can usually drive with this code, but schedule a diagnosis soon to prevent potential problems.

How much does it cost to fix P0146? ▾

Repair costs vary widely depending on the root cause. Diagnosis typically costs $80-$150. Repairs can range from $50 for simple fixes to $500+ for major component replacements. Always get a diagnosis before authorizing repairs.

🏥 When to See a Mechanic

If you're not comfortable with electrical diagnosis or don't have a multimeter and OBD-II scanner, have a qualified mechanic diagnose P0146. This code involves the fuel and air metering (injector circuit) system which may require specialized knowledge.

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Disclaimer: This information is for educational purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. Always consult a qualified mechanic for diagnosis and repair. Repair costs shown are estimates and may vary by location, vehicle, and shop.