P0474: Exhaust Pressure Sensor A Circuit Intermittent/Erratic
What to do
Driveable. Note whether the light appears only once the engine is thoroughly warm, which points at a heat-related connection.
What this code means
The exhaust pressure signal is dropping out or jumping erratically. Given the sensor's position, heat cycling on the connector and harness is the usual mechanism — a joint that is sound when cold opens as the exhaust warms, which makes the fault appear after a few minutes of running and disappear overnight.
Likely causes
Start here
- Damaged wiring harness near exhaust heat · moderate
- Corroded or loose connector · easy
- Intermittent open in sensor wiring · moderate
Less common
- Faulty exhaust back pressure sensor · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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