Exhaust Pressure Sensor Intermittent
Your exhaust pressure sensor is sending inconsistent signals to the engine computer, like a radio that keeps cutting in and out. The ECU can't reliably monitor exhaust backpressure, which affects emissions control and engine performance.
The ECM monitors the exhaust pressure sensor voltage signal to track exhaust system backpressure and EGR flow. An intermittent fault occurs when the sensor signal drops out temporarily or fluctuates beyond expected ranges, preventing reliable emissions diagnostics.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor Voltage | 0.5–4.5 volts steady | Erratic transitions or signal loss >500ms |
| Exhaust Pressure | 2–8 kPa at idle | Intermittent dropout or >10 kPa spikes |
Code P0475 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, P0475 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.