P0473 Exhaust Pressure Sensor High

P0473 indicates a high signal from the exhaust pressure sensor. The controller sees exhaust pressure voltage or feedback above the expected range.

Code details

Generic OBD-II · P0

System: Emissions
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not ignore true high exhaust pressure while diagnosing the sensor circuit.

Symptoms of P0473

Check-engine light, often with no obvious change in how the car drives.
A failed emissions test or incomplete readiness monitors.
Sometimes a faint fuel-vapour smell (on EVAP codes).

Common causes of P0473

A worn catalytic converter or an oxygen/air-fuel sensor reading out of range.
EVAP leaks — a loose or failed gas cap, cracked hose, or purge/vent valve.
Exhaust leaks, fuel-trim problems, or a fault in a related monitor.

Useful checks before replacing parts

Review exhaust pressure sensor voltage, reference voltage, ground integrity, engine load, boost, DPF status where equipped, and freeze-frame data.
Inspect for short-to-voltage faults, open grounds, blocked or restricted exhaust paths, soot-plugged sensor tubes, and damaged sensor wiring.
Compare pressure readings key-on, idle, and under load to identify a stuck-high signal versus true excessive backpressure.

Related OBD-II codes

These nearby emissions entries can help compare wording and pin down the fault area.