P0473: Exhaust Pressure Sensor A Circuit High
Do not keep driving
If the car has also lost power, will not rev freely, or is running hot, stop driving it and have it recovered — a blocked exhaust can damage the engine and is a fire risk near a glowing converter. If it drives entirely normally, the fault is more likely electrical, but the exhaust restriction still needs ruling out before the sensor is replaced.
What this code means
The exhaust pressure signal is above its plausible range. The electrical causes are the usual ones — an open ground, or a signal wire finding a supply — but there is a mechanical cause here that must be excluded before the sensor is blamed, because it is genuinely serious.
A blocked exhaust really does produce very high back pressure. A particulate filter packed with soot, or a catalytic converter whose substrate has melted and collapsed, restricts the exhaust to the point that the engine cannot breathe. The car will feel gutless, refuse to rev, and may overheat. Treating that as a faulty sensor and clearing the code leaves a vehicle that is about to destroy something expensive.
Likely causes
Start here
- Blocked or restricted exhaust · specialist
- Broken or collapsed converter substrate · specialist
- Open sensor ground circuit · moderate
- Faulty exhaust back pressure sensor · moderate
Less common
- Signal wire shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
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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