Emissions control: EGR, DPF, catalytic converter and AdBlueGeneric OBD-II codeUrgency: Garage soon
Code P0471: exhaust pressure sensor: implausible signal
P0471 means: exhaust pressure sensor range/performance (signal out of range or not consistent with engine operation).[1][2] The control unit has detected that the exhaust pressure sensor signal is outside what is expected or does not match the engine's operating conditions. It is a plausibility fault: the electrical value falls within the range, but is not consistent with what the sensor should be measuring. This sensor is key mainly on diesels for managing the turbo, exhaust gas recirculation (EGR) and emissions control; according to Autobiz, the one carrying this code is usually the manifold sensor, upstream of the turbo, which is used to protect the turbo, control the variable geometry vanes and calculate the EGR flow.[2][3][4]
What code P0471 means
The control unit has detected that the exhaust pressure sensor signal is outside what is expected or does not match the engine's operating conditions. It is a plausibility fault: the electrical value falls within the range, but is not consistent with what the sensor should be measuring. This sensor is key mainly on diesels for managing the turbo, exhaust gas recirculation (EGR) and emissions control; according to Autobiz, the one carrying this code is usually the manifold sensor, upstream of the turbo, which is used to protect the turbo, control the variable geometry vanes and calculate the EGR flow.[2][3][4]
It should not be confused with the codes for the particulate filter differential sensor (such as P2453), which measures the pressure drop across the DPF: Autobiz describes them as parts that are rarely interchangeable. But the make matters: on VW group diesels with 1.6 and 2.0 TDI engines, Autobiz identifies the "Exhaust Pressure Sensor 1 (G450)" as the DPF sensor, and Ross-Tech links that same sensor to both P0471 and P2453. On those cars, a P0471 can point to the particulate filter sensor.[4][5][6]
It is a generic OBD-II code (it starts with P0), with the same definition on any make; what changes from one car to another is which specific sensor is monitored.[7]
Original definition (SAE J2012): Exhaust Pressure Sensor Range/Performance[1][2]
Causes of P0471
From most to least likely, according to the sources.
- 1Faulty or incompatible exhaust pressure sensor. Ross-Tech notes that on VAG cars the code often indicates that the wrong sensor has been fitted: there are two types depending on the model year.[3][5]
- 2Blocked sensor pickup pipe or hose: carbon or soot clogs the pipe that carries the pressure to the sensor, especially the hollow (banjo) bolt on the connection.[3][4][5]
- 3Damaged, corroded or loose sensor wiring or connectors.[3][5]
- 4A problem in the exhaust gas recirculation (EGR) system.[3]
- 5Faulty control unit, although this is uncommon.[3]
Symptoms
- Engine warning light on.[3][5]Engine warning light: faults that cause it
- On some cars, loss of engine performance.[3]Less power: faults that cause it
- Other codes related to the exhaust or the turbo may also be stored.[3]
- On some BMWs, when the sensor upstream of the turbo gets blocked with soot, the "Drivetrain Malfunction" warning appears and the turbo responds with a delay.[4]
How to diagnose P0471
In order: from the most likely and cheapest to check to the most expensive.
- 1Read the codes with the diagnostic tool, clear them and check whether the code returns. Also check the other exhaust, turbo and EGR codes.[3]
- 2Find out which sensor the code monitors on your engine: the manifold pressure sensor (upstream of the turbo) or, on many VAG cars, the particulate filter sensor. The manufacturer's diagram shows this, and they are not interchangeable parts.[4][5]
- 3Inspect the sensor wiring and connectors: corrosion, damaged wires or wires chafed by heat.[3][5]
- 4Check the pipe or hose that carries the exhaust pressure to the sensor. If it is blocked by carbon, clean it: Autobiz suggests heating the pipe or the hollow bolt with an induction heater while blowing compressed air from the disconnected sensor side.[3][4][5]
- 5Compare the readings with those of the other pressure sensors. On VW group cars, if with the engine off one sensor reads 0 mbar and another 50 mbar, the control unit logs a correlation fault.[4]
- 6Check that the fitted sensor is the correct one for the engine and year (part number): a wrong sensor can trigger this code on VAG cars.[5]
- 7Check the EGR system, which may also be behind the code.[3]
- 8Replace the sensor only if the previous tests point to it.[3][5]
Can I keep driving with P0471?
Garage soon
The sources give little information on severity. Autodoc Club says, in general terms, that you can drive for a short period, but that the code must be corrected as soon as possible. Because this reading is used to protect the turbo, control the variable geometry and calculate the EGR flow (Autobiz), and on VW group diesels the same sensor is involved in controlling the particulate filter (Ross-Tech), it should be diagnosed soon.[1][4][6]
Documented faults related to P0471
Known faults of specific engines and cars, with their repair cost, the affected years and their sources.
Engine sensors: the most serious faults by engine and car
- High severityOccasionalFrequency: Occasional2.0 DTI and 2.2 DTIVP44 injection pump and air mass meter failureGerman Wikipedia documents recurring failures of the Bosch VP44 injection pump and the air mass meter in the early years of this engine. An owner testimony for this engine describes the pump being replaced at 192,500 km, at a cost the owner calls «prohibitive».
- Medium severityCommonFrequency: Common2.0 TDIClogged particulate filter or faulty pressure sensorThe 2.0 TDI's particulate filter clogs if the car mostly makes short journeys, because it never gets to regenerate; sometimes the fault is just the differential pressure sensor. Cleaning it costs around €200 and replacing it, €800 to €3,000.Repair (garage): €800–€3,000
- Medium severityCommonFrequency: Common1.4 and 1.6 8vCrankshaft position sensor failure (TDC sensor)The crankshaft position sensor (capteur PMH, or TDC sensor) appears repeatedly in the reliability sources for the Clio II, the Kangoo I and the Dacia Logan I with this engine, with hard cold starting or stalling as the main symptoms. It is a cheap part, but the failure can leave you stranded.
- Medium severityCommonFrequency: Common1.4 and 1.6 16vCrankshaft position sensor failureThe crankshaft position sensor (capteur PMH) appears repeatedly in the reliability sources for almost every generation with this engine, with hard cold starting, stalling or the car cutting out unexpectedly. It is a cheap part, but the failure can leave you stranded.
EGR valve: the most serious faults by engine and car
- Critical severityVery frequentFrequency: Very frequentBMW B47EGR cooler leaks with risk of engine fireYes: the EGR valve cooler can suffer internal coolant leaks which, mixed with soot and oil, can reach combustion temperatures; BMW has launched several technical campaigns since 2018 to inspect and replace it because of the risk of engine fire.Repair (garage): €500–€1,500
- Critical severityVery frequentFrequency: Very frequentBMW N57EGR cooler leaks with risk of engine fireYes: like the N47 and B47, the N57 is covered by BMW's service campaign for EGR cooler leaks, which can mix coolant with soot and oil to combustion temperatures. BMW checks free of charge the 6-cylinder engines built between July 2012 and June 2015 because of the fire risk.
- High severityVery frequentFrequency: Very frequentOM651EGR and particulate filter clogging, and emissions software updatesThe particulate filter and EGR clog up with short journeys, as on any diesel with these systems. In addition, Germany's KBA required software updates on several models with this engine between 2018 and 2021 because of a function that reduced EGR outside a temperature range.Repair (garage): €800–€2,500
- Medium severityVery frequentFrequency: Very frequentOM642Emissions defeat device (AdBlue/EGR) and software update campaignGermany's KBA found indications of emissions manipulation in cars with the OM642 engine (alongside the OM651): AdBlue dosing and the EGR changed between the test bench and the road. Mercedes-Benz denied it, but in 2018 it recalled hundreds of thousands of diesels in Europe.
Turbo: the most serious faults by engine and car
- High severityVery frequentFrequency: Very frequent1.6 HDiTurbo failure through lack of lubrication (carbon deposits and union filter)On the 16-valve 1.6 HDi/TDCi engines (2004-2011) the turbo can seize because carbon deposits from the oil clog the mesh filter in the union that feeds it. It is a serious, repeat fault: if only the turbo is replaced without cleaning the circuit, it fails again.Repair (garage): €700–€1,050
- High severityVery frequentFrequency: Very frequent2.0 Ingenium diéselTurbocharger failureYes: according to several sources, the turbo is the component that causes the most faults on the 2.0 Ingenium diesel. It fails across a very wide mileage range (from around 35,000 to over 140,000 km) and, if it breaks up inside, it can send oil or metal into the engine and destroy it.Repair (garage): €2,600–€3,000Appears at around 35,000 km
- High severityCommonFrequency: CommonBMW N47Turbo and wastegate valve failureThe N47's turbo does not usually fail from general wear, but because of failure of the wastegate valve, which regulates boost and can seize or lose adjustment, sending fuel consumption soaring; oil leaks from the turbo itself are also common.Repair (garage): €900–€1,800
- High severityCommonFrequency: CommonOM651Variable-geometry turbo failure and its pneumatic actuatorThe OM651's variable-geometry turbo tends to fail at the pneumatic actuator (cracks, loss of calibration) before the turbo itself. Symptoms range from a gradual loss of power to permanent limp mode, with whistling or smoke if the problem progresses.Repair (garage): €500–€3,000
Particulate filter (DPF/FAP): the most serious faults by engine and car
- High severityVery frequentFrequency: Very frequentOM651EGR and particulate filter clogging, and emissions software updatesThe particulate filter and EGR clog up with short journeys, as on any diesel with these systems. In addition, Germany's KBA required software updates on several models with this engine between 2018 and 2021 because of a function that reduced EGR outside a temperature range.Repair (garage): €800–€2,500
- High severityCommonFrequency: Common1.3 MultijetIncomplete particulate filter regenerations and oil dilutionIn heavy urban use, with short journeys that do not let the particulate filter regeneration finish, unburnt diesel passes into the sump and dilutes the oil; the level can rise on the dipstick and the oil loses its ability to lubricate. Repeated many times, it speeds up engine wear.
- High severityCommonFrequency: Common2.0 HDiDPF clogging on additive-type systems (Eolys/cerine)The additive-type diesel particulate filter (DPF) of the 2.0 HDi clogs relatively easily on short journeys, especially on the 107/110 and 136-140 hp versions. The anti-pollution warning light comes on and, if ignored, the car loses power and may end up needing a new DPF.
- High severityCommonFrequency: Common1.6 and 2.0 MultiJet IISaturated diesel particulate filter (DPF) from incomplete regenerationsIn urban use with short journeys, the particulate filter does not manage to complete its regeneration and becomes saturated; garages recommend a weekly motorway run to avoid it. The filter itself is among the weak points flagged in the 1.6 and 2.0 MultiJet II after a certain mileage.
Wiring, connectors and short circuits: the most serious faults by engine and car
- Critical severityOccasionalFrequency: OccasionalBMW N62 / N63Additional turbo coolant pump with a risk of short circuit and fireIn 2011 BMW recalled 5, 6 and 7 Series, X5 and X6 models built between 2007 and 2011 because of the additional turbo coolant pump: moisture, a short circuit and, in extreme cases, a fire. In 2012 there was another campaign for a crack in the pump, with a more robust version.
- High severityOccasionalFrequency: Occasional1.3 TCeBlown fuel pump fuseOn the Renault Captur II and Clio V with the 1.3 TCe engine, a 20-amp fuse can blow and leave the car without an engine. According to L'argus, in April 2021 this fault still had no factory fix; the official service centre's diagnosis includes checking, and sometimes replacing, the catalytic converter.
- High severityOccasionalFrequency: OccasionalM264/M254Poorly tightened 48 V earth wiring in the mild-hybrid system (fire risk)Mercedes-Benz has issued several recalls (2022-2025) because the 12 V and 48 V earth connections of some cars with a 48 V system may be poorly tightened: resistance rises, the connection heats up and a fire cannot be ruled out. The official workshop checks them and repairs them if necessary in an hour or more.
- High severityOccasionalFrequency: Occasional1.9 TDIUnit injector tappet wear and injector wiring damageOn the unit injector system, the tappets that operate the injectors can wear if the oil is not changed on time, and the injector wiring can be damaged by contact with oil, causing misfires or loss of power.
- Critical severityOccasionalFrequency: OccasionalAlfa Romeo GiuliettaShort circuit from badly routed wiring that can prevent gear shifting (KBA campaign, 2010-2015)Yes: according to Germany's KBA, on Alfa Romeo Giulietta cars built between 2010 and 2015 inadequate cable routing could cause a short circuit and, as a result, gear-shift failure.
- Critical severityOccasionalFrequency: OccasionalAudi A4 B9Risk of short circuit and fire due to moisture in electrical componentsAudi recalled A4 B9 units built between May 2017 and March 2020 because moisture can seep into an electrical component and cause a short circuit, with a risk of the vehicle catching fire.Repair: €0
Frequently asked questions
What is the difference between P0471 and the particulate filter sensor codes?
P0471 refers to the exhaust pressure sensor; according to Autobiz, normally the manifold one upstream of the turbo, which is used to protect the turbo, control the variable geometry and calculate the EGR flow. The particulate filter differential sensor, which measures the pressure drop across the DPF, has its own codes, such as P2453. They are different parts, although on VW group diesels the "Exhaust Pressure Sensor 1 (G450)" sensor is linked to both P0471 and P2453.[4][5][6]
Can I drive with code P0471?
Autodoc Club says it is possible to drive for a short period, but that the code must be corrected as soon as possible. Because the sensor is used to manage the turbo and the EGR, it is best not to put it off.[1][4]
Does the exhaust pressure sensor have to be replaced?
Not necessarily. First check the wiring and connectors, and whether the pipe that carries the pressure to the sensor is blocked by carbon, which is common. On VAG cars, you also need to verify that the sensor is the correct one for the model year.[3][4][5]
Does P0471 affect only diesels?
Not exclusively, but this sensor is monitored mainly on turbocharged cars and diesels, where it is key to managing the turbo, the EGR and emissions.[2][3]
Does P0471 mean the same on all makes?
The definition does: codes that start with P0 are generic OBD-II codes. What changes is which specific sensor the code monitors on each engine, so it is worth consulting the manufacturer's diagram.[4][5][7]
Will I pass the MOT with code P0471?
If the code has switched on the engine warning light, no: with that light on, the inspection records a serious defect, and on Euro 5 and Euro 6 cars the ITV (Spain's roadworthiness inspection, similar to the MOT) also reads the OBD diagnostic system. Repair the fault before you go; clearing the code just before the inspection does not help either, because it counts as a serious defect.[8]
Not sure what is wrong with your car? Describe what you notice in the symptom diagnosis or see all fault codes.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- 1.Código de avería P0471: guía paso a paso para su diagnóstico y resoluciónAutodoc Club · Technical documentation · consulted 2 October 2026 · in Spanish
- 2.P0471 - Exhaust Pressure Sensor Range/Performance | TaTThe Automotive Technician (TaT) · Technical documentation · consulted 2 October 2026
- 3.PartsAvatar - OBD Engine Error Code P0471 SolutionPartsAvatar · Technical documentation · published 2 June 2022 · consulted 2 October 2026
- 4.Exhaust pressure vs DPF pressureAutobiz.ie · Motoring press · published 1 May 2026 · consulted 2 October 2026
- 5.16855/P0471/001137 - Exhaust Pressure Sensor 1 (G450): Implausible SignalRoss-Tech · Technical documentation · consulted 2 October 2026
- 6.18885/P2453/009299 - Diesel Particle Filter Differential Pressure Sensor: Implausible SignalRoss-Tech · Technical documentation · consulted 2 October 2026
- 7.On-board diagnosticsWikipedia · Other source · consulted 2 October 2026
- 8.Desmontando mitos: ¿puede pasar mi coche la ITV con el testigo de «avería motor» encendido?Diariomotor · Motoring press · published 8 March 2021 · consulted 2 October 2026 · in Spanish