P0474
UniversalExhaust Pressure Sensor Intermittent
Medium SeverityThe vehicle's computer has detected an inconsistent signal from the Exhaust Pressure Sensor, which monitors exhaust gas pressure. This intermittent issue can lead to unreliable engine performance data, potentially affecting emissions system operation or turbocharger control.
⚠️ Before You Begin (Safety First)
Always ensure the engine is off and cool before working on exhaust components. Wear appropriate personal protective equipment, including gloves and eye protection. Disconnect the battery before performing any electrical work to prevent accidental shorts or shocks. Be aware that exhaust components can be very hot and cause severe burns.
Common Symptoms
- Check Engine Light illumination
- Reduced engine performance or power
- Poor fuel economy
- Excessive exhaust smoke (especially in diesel engines)
- Failed emissions test
- Issues with Diesel Particulate Filter (DPF) regeneration (diesel engines)
Common Causes
- Faulty exhaust pressure sensor
- Corroded or damaged wiring or connector to the sensor
- Blocked or clogged exhaust pressure sensor tube
- Exhaust system leaks causing incorrect pressure readings
- Damaged Powertrain Control Module (PCM) (rare)
Frequently reported on: Ford F-Series (2008-2016), Ram 2500/3500 (2007-2012), Chevrolet Silverado/GMC Sierra (2007-2010), General/Universal Diesel Vehicles
Diagnostic Steps
- Visually inspect the exhaust pressure sensor and its wiring harness for any obvious damage, corrosion, or loose connections.
- Check the pressure sensor hose for cracks, blockages, or disconnections, especially the tube leading to the exhaust manifold or DPF.
- Use a multimeter to test the sensor's electrical circuit for proper voltage supply and ground.
- If accessible, carefully remove the sensor and clean any carbon buildup from its tip or sensing port.
- Clear the P0474 code using an OBD-II scanner and test drive the vehicle to see if the code returns.
- If the code persists after inspection and cleaning, consider replacing the exhaust pressure sensor.
👨🔧 When to Call a Professional
If after basic diagnostics and sensor inspection, the issue persists or if you experience significant performance problems like sustained loss of power, it's best to consult a qualified mechanic to diagnose complex electrical or exhaust system faults.
Commonly Asked Questions
What does 'intermittent' mean for the P0474 code?
It means the exhaust pressure sensor's signal to the engine computer is not consistently within expected parameters, sometimes working correctly and sometimes not.
Can I drive with an intermittent exhaust pressure sensor code?
While you might be able to drive, it's not recommended long-term as it can lead to reduced performance, poor fuel economy, and potential damage to the emissions system, especially in diesel vehicles.
Where is the exhaust pressure sensor located?
Its location varies by vehicle but it's typically found on the exhaust manifold or near the Diesel Particulate Filter (DPF) on diesel engines, or on the exhaust system on some gasoline engines.
Is P0474 a common problem?
Yes, especially in diesel vehicles equipped with DPF systems, where these sensors can get clogged or fail due to heat and soot buildup, leading to intermittent readings.
Do I need special tools to fix P0474?
An OBD-II scanner is essential for reading and clearing the code. Basic hand tools like wrenches and a multimeter will be helpful for inspection and replacement. A vacuum pump might be needed to test pressure lines.