Mass Air Flow (MAF) Circuit Intermittent
What does P0104 mean?
The P0104 code means the vehicle's onboard diagnostic system has detected: Mass Air Flow (MAF) Circuit Intermittent. This is a moderate severity code.
Common Symptoms
- Check Engine Light on, may be intermittent
- Engine surging or hesitation at varying speeds
- Rough or erratic idle
- Stalling at idle or low speeds
- Poor fuel economy and inconsistent power delivery
Probable Causes (Ranked by Likelihood)
- Loose or damaged MAF sensor connector Very High
- Cracked or loose air intake duct between MAF and throttle body High
- Intermittently failing MAF sensor High
- Damaged wiring or chafed insulation in MAF circuit Moderate
- Contaminated MAF sensor element Moderate
Step-by-Step Diagnostic Procedure
-
Inspect the MAF sensor connector for loose, corroded, or bent pins. Wiggle the connector while monitoring MAF readings on a scan tool to check for dropouts.
-
Check the air intake duct between the MAF sensor and throttle body for cracks, loose clamps, or splits. Unmetered air causes erratic readings.
-
Monitor MAF sensor readings at idle (typically 2-7 g/s) and at 2,500 RPM (15-25 g/s). Sudden drops to 0 or erratic spikes indicate an intermittent failure.
-
Inspect the wiring harness from the MAF sensor to the PCM for chafing, broken strands, or corroded splice points.
-
Clean the MAF sensor element with MAF-specific cleaner spray. Do not touch the hot wire or film element. Let it dry completely before reinstalling.
Frequently Asked Questions
Can I drive with code P0104?
You can drive short distances, but the intermittent MAF signal can cause unpredictable surging, hesitation, or stalling. This makes the vehicle unreliable, especially in traffic. Diagnose it promptly.
What makes P0104 different from P0101?
P0101 indicates the MAF reading is out of expected range, while P0104 indicates the signal is intermittent -- it cuts in and out. P0104 usually points to a wiring or connector issue rather than a failed sensor.
Can I clean a MAF sensor instead of replacing it?
Yes, cleaning with MAF-specific cleaner resolves the issue in many cases, especially if the sensor element is contaminated with oil or dirt from a reusable air filter. Use only MAF cleaner -- never carb cleaner or brake cleaner.