OBD Code P0107: MAP Sensor Low Input – Causes & Fixes

Quick Answer

What Does P0107 Mean?

The P0107 diagnostic trouble code indicates that your vehicle’s engine control module (ECM) has detected an abnormally low voltage signal from the Manifold Absolute Pressure (MAP) sensor. The MAP sensor measures the air pressure inside the intake manifold and sends this data to the ECM, which uses it to calculate the correct air-fuel mixture for combustion.

When the ECM receives a voltage signal that’s lower than the expected range (typically below 0.5 volts), it triggers the P0107 code. This low signal tells the ECM that manifold pressure is extremely high (or vacuum is extremely low), which shouldn’t occur during normal operation. In response, the engine control module enriches the fuel mixture to compensate, resulting in a “rich” running condition.

This is a moderate severity code that affects fuel economy and engine performance but typically won’t prevent your vehicle from starting or running.

Common Symptoms

• Check Engine Light (CEL) – Illuminated on your dashboard
• Poor Fuel Economy – Noticeably worse MPG due to rich fuel mixture
• Rough Idle – Engine stumbles or vibrates at stops
• Black Smoke from Exhaust – Sign of unburned fuel (rich condition)
• Engine Hesitation or Stumbling – Especially during acceleration
• Difficulty Starting – Cold starts may be sluggish
• Strong Fuel Smell – Unburned fuel odor from exhaust
• Reduced Power – Engine may feel sluggish or lack responsiveness

Possible Causes

Listed from most to least common:

1. Faulty MAP Sensor

The most common cause. The sensor itself may have failed internally, producing an incorrect low voltage signal even when manifold pressure is normal. MAP sensors can fail due to age, contamination, or electrical degradation.

2. Vacuum Leak

A leak in the vacuum system (intake manifold gasket, hoses, or connections) allows unmetered air into the engine, causing the MAP sensor to read lower pressure than it should. This is the second most common cause.

3. Dirty or Clogged Intake Manifold

Carbon buildup in the intake manifold can restrict airflow and cause pressure readings to drop, triggering the code. This is more common in high-mileage vehicles.

4. Faulty MAP Sensor Wiring or Connectors

Corroded, loose, or damaged wiring between the MAP sensor and ECM can cause signal transmission errors. Water intrusion or corrosion in the connector is a common culprit.

5. Intake Air Leak Before the MAP Sensor

A leak in the air intake system before the MAP sensor (between the air filter and throttle body) can cause the sensor to read abnormally low pressure.

6. ECM Software Issue or Faulty ECM

Rarely, a problem with the engine control module itself or outdated software can cause false P0107 codes. This is typically a last-resort diagnosis.

7. Blocked Air Filter or Intake Obstruction

A severely clogged air filter or obstruction in the intake tract can reduce manifold pressure and trigger the code.

Diagnostic Steps

Step 1: Scan for Additional Codes

Connect an OBD-II scanner to your vehicle’s diagnostic port (usually under the dashboard on the driver’s side). Note all codes present. Related codes like P0106, P0108, or P0101 may provide additional clues about the problem.

Step 2: Perform a Visual Inspection

Check the following:

• Inspect the MAP sensor connector for corrosion, moisture, or loose pins
• Check the MAP sensor wiring for damage, cuts, or exposed areas
• Look for obvious vacuum hose leaks, cracks, or disconnected hoses
• Inspect the intake manifold gasket for signs of leakage (oil or coolant)
• Check the air filter for excessive dirt or blockage

Step 3: Check for Vacuum Leaks

With the engine running, listen for hissing sounds around the intake manifold and vacuum hoses. You can also spray a light mist of water around suspected leak areas – if the idle changes, you’ve found a leak. Alternatively, use a smoke test machine to identify vacuum leaks more precisely.

Step 4: Test the MAP Sensor Voltage

Using a digital multimeter set to DC voltage mode:

• Locate the MAP sensor (consult your vehicle’s service manual for location)
• With the key in the “On” position (engine off), measure the voltage at the sensor’s signal wire
• Typical readings should be around 4.5-5 volts at idle; a reading below 0.5 volts confirms a low signal
• Start the engine and observe voltage changes – it should vary as engine load changes
• If voltage doesn’t change or stays at 0V, the sensor is likely faulty

Step 5: Check MAP Sensor Vacuum Supply

Inspect the vacuum hose connected to the MAP sensor:

• Ensure the hose is connected securely at both ends
• Look for cracks, splits, or deterioration
• Check that the hose is routed correctly and not pinched
• Replace the hose if damaged

Step 6: Inspect the Intake Manifold

Remove the intake manifold cover (if applicable) and look for:

• Carbon buildup or deposits
• Gasket leaks or oil seepage
• Cracks in the manifold itself
• If carbon buildup is present, the manifold may need cleaning

Step 7: Test the ECM Circuit

If the MAP sensor and wiring appear normal, test the ECM’s sensor circuit:

• Check the reference voltage (typically 5V) supplied to the MAP sensor
• Verify the ground connection is solid
• If reference voltage is absent or low, the ECM may be faulty

Step 8: Replace the MAP Sensor

If all tests point to a faulty sensor, replacement is the solution. Most MAP sensors are simple bolt-on components that take 15-30 minutes to replace. After replacement, clear the code and test drive to confirm the fix.

Repair Cost Estimates

MAP Sensor Replacement

• Parts Cost: $50–$200 (depending on vehicle make/model)
• Labor Cost: $75–$150 (15–30 minutes of shop time)
• Total: $125–$350

Vacuum Leak Repair

• Hose Replacement: $30–$100 (parts and labor)
• Intake Manifold Gasket Replacement: $200–$600 (more labor-intensive)
• Total: $30–$600 (depending on leak location)

Intake Manifold Cleaning

• Parts Cost: $0–$50 (cleaning supplies)
• Labor Cost: $150–$400
• Total: $150–$450

Wiring or Connector Repair

• Parts Cost: $10–$50
• Labor Cost: $50–$100
• Total: $60–$150

DIY Note: If you have basic automotive knowledge and tools, replacing a MAP sensor is a straightforward DIY job that can save you $75–$150 in labor costs.

Can I Still Drive?

Yes, but with caution. P0107 is a moderate severity code that typically won’t prevent your vehicle from running. However, you should address it promptly for these reasons:

• Fuel Economy: You’ll experience noticeably worse gas mileage, costing you extra money at the pump
• Engine Performance: Rough idle, hesitation, and reduced power make driving less comfortable and responsive
• Emissions: The rich fuel mixture increases emissions and may cause your vehicle to fail an emissions test
• Catalytic Converter Risk: Prolonged running in a rich condition can damage your catalytic converter due to excess unburned fuel, leading to a much more expensive repair ($800–$2,000)
• Engine Damage: Extended operation with a faulty MAP sensor can cause carbon buildup and potential long-term engine damage

Recommendation: Diagnose and repair the issue within a week or two. Don’t ignore this code for months, as it can lead to secondary damage and higher repair costs.

Frequently Asked Questions

Can a vacuum leak cause P0107?

Yes, absolutely. A vacuum leak is one of the most common causes of P0107. When air leaks into the intake manifold before the throttle body, it bypasses the MAP sensor’s measurement, causing the sensor to read lower pressure than expected. Inspect all vacuum hoses for cracks, loose connections, and deterioration. A smoke test can help identify hard-to-find leaks.

Will clearing the code fix P0107?

Clearing the code will temporarily turn off the Check Engine Light, but the underlying problem remains. The code will return within a few driving cycles if the root cause isn’t fixed. Always diagnose and repair the actual problem rather than just clearing the code. Temporary fixes include clearing codes, but permanent solutions require identifying whether it’s a faulty sensor, vacuum leak, wiring issue, or intake problem.

How much does it cost to fix P0107?

Repair costs range from $60–$600 depending on the cause. A faulty MAP sensor replacement typically costs $125–$350. Vacuum leak repairs range from $30–$600 depending on location. Intake manifold cleaning costs $150–$450. If you suspect a faulty ECM (rare), costs could exceed $1,000. Most commonly, a MAP sensor replacement solves the problem for under $300.

Can I drive with P0107 code?

Yes, you can drive with P0107, but it’s not recommended for extended periods. The code indicates a rich fuel mixture, which reduces fuel economy, causes rough idle, and can damage your catalytic converter over time. Address the issue within a week or two to avoid secondary damage. Continued driving with this code may result in a failed emissions test and potential catalytic converter damage costing $800–$2,000.