What does P0474 mean?
The exhaust back pressure sensor measures pressure in the exhaust manifold on many diesels. The computer uses it for EGR and turbo control.
The signal is dropping out or jumping erratically for short periods.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Reduced power
- Turbo or EGR related drivability issues
Common causes
- Loose connector or chafed wire that loses contact over bumps
- Corrosion in the connector
- Sensor failing intermittently
How to diagnose P0474
- Wiggle-test the harness while watching live data for dropouts.
- Check the connector terminals for spread pins and corrosion.
- Check the harness where it passes brackets, the engine and hot exhaust parts.
- Key on, engine off, the reading should match barometric pressure.
- Remove and clear the sensor tube.
How to fix it
- Clean the sensor tube
- Replace the sensor
- Repair wiring
Estimated repair cost
Likely repairs for P0474 run from about $100 to $350, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Exhaust back pressure sensor | $100 - $350 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0474?
Moderate severity
Usually drivable, possibly with reduced power.
P0474 FAQ
What does P0474 mean?
P0474 stands for "Exhaust Pressure Sensor "A" Circuit Intermittent (Bank 1)". The exhaust back pressure sensor measures pressure in the exhaust manifold on many diesels.
Can I drive with a P0474 code?
Usually drivable, possibly with reduced power.
How much does it cost to fix P0474?
It depends on the cause. The likely repairs for P0474 range from about $100 to $350 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0474?
The most common causes are: loose connector or chafed wire that loses contact over bumps; corrosion in the connector; sensor failing intermittently.