Fuel Trim too Lean (Bank 2)
Your engine's computer detected that Bank 2 (the side without cylinder #1) is running too lean—meaning there's not enough fuel compared to air. Think of it like a recipe with too much water and not enough flour; the mixture is out of balance.
The ECU monitors oxygen sensor voltage on Bank 2 to calculate fuel trim corrections. When the O2 sensor reads consistently lean (high voltage), the ECU tries to add fuel, but if it hits maximum correction limits, it triggers P0175. This indicates a fuel delivery or air metering problem.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Long-term fuel trim (Bank 2) | -10% to +10% | >+25% correction needed |
| O2 sensor voltage (Bank 2) | 0.4–0.6V (switching) | Consistently >0.7V (lean) |
Code P0175 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, P0175 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.