P0471: Exhaust Pressure Sensor "A" Circuit Range/Performance

P0471 is a emissions-related diagnostic trouble code classified as moderate severity.

• Check engine light on
• Often no change in how the car drives at first
• DPF warning light on some models, sometimes appearing later because regeneration has stopped or is running too often
• Reduced power or limp mode on some vehicles
• Higher fuel consumption if regeneration runs more often than it should
• P0470, or a DPF pressure code such as P2453, stored alongside on some cars

Generally yes, for short-term driving. Driveable in the short term, and the car often feels normal at first. Do not leave it for weeks: without a trustworthy exhaust pressure signal the engine computer may suspend particulate filter regeneration or fall back on an estimate, and some cars limit power. A filter that goes too long without regenerating can block, which turns a sensor, hose or wiring repair into a DPF clean or replacement.

1. Read all stored codes and the freeze frame. Note whether P0470 or a DPF code (P2452 to P2455, P244A, P244B or P2463) is stored alongside, and note the engine speed and load when the fault set. A generic OBD2 reader shows this code, its freeze frame and standard live data. A few diesels also report exhaust or DPF pressure on a standard PID, but on most cars the pressure reading, the soot load and the regeneration history need manufacturer-level software, and only that software or a workshop can run a forced regeneration or adapt a new sensor.
2. Find out which sensor is exhaust pressure sensor "A" on your engine: a back pressure sensor near the exhaust manifold or turbo, a sensor before the particulate filter, or on many Volkswagen group TDIs the DPF differential pressure sensor. Check the workshop information for your engine code.
3. With the engine cold, trace the sensing pipes and hoses from the exhaust to the sensor. Look for split, melted, kinked or disconnected hoses, and on a differential sensor check that the two hoses go to the right ports, because swapped hoses give a plausible but wrong reading.
4. Disconnect the pipes and check they are clear. The metal pipes near the exhaust can fill with soot, and blowing through them or clearing them with a wire usually shows a blockage.
5. With manufacturer-level software, compare the pressure reading with the engine off and then at idle and higher revs. With the engine off it should read close to zero, or close to outside air pressure on an absolute sensor, and it should rise smoothly with revs. A reading that is stuck, jumps or is far off at rest points to the sensor.
6. Check for exhaust leaks before the sensing point, and for boost or EGR leaks, which change exhaust flow and pressure.
7. Replace the sensor with the correct part for the engine code if the pipes and hoses are good, run the sensor adaptation if the engine computer asks for one, clear the code and road-test. If the filter is genuinely loaded, a forced regeneration or a clean comes next.