EGI Mini - MAF Failed Out Of Range
The Mass Air Flow (MAF) sensor is sending a signal outside its normal range, like a speedometer needle stuck too far left or right. The engine computer can't accurately measure how much air is entering, disrupting fuel mixture calculations.
The ECU monitors the MAF sensor's voltage output, which should vary smoothly between 0.4V and 5V as airflow changes. When the signal stays consistently too high or too low, the ECU can't trust the reading and triggers the fault. This causes incorrect fuel injection timing and amount.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| MAF Sensor Voltage | 0.4V to 5.0V (dynamic range) | Below 0.4V or above 5.0V; static/unchanging signal |
| Air Mass Flow Rate | Proportional to engine load (typically 3-7 g/s at idle) | Reading exceeds ECU calibration limits or fails to respond |
Code P1433 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1433 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.