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P0470 OBD-II Trouble Code: Exhaust Pressure Sensor Malfunction

check engine light

P0470 code definition

P0470 is a code that means the sensor in charge of assessing exhaust pressure isn’t working properly.

What the P0470 code means

This code means that the signal being provided by the exhaust pressure sensor isn’t matching the ambient air pressure or manifold pressure. It’s associated with code P0471. The only difference between the two is how long the problem has persisted for the electrical/mechanical problem the vehicle is having.

What causes the P0470 code?

There are five main issues that could be behind a P0470 code:

  • The exhaust back pressure sensor is faulty
  • The exhaust back pressure sensor harness is shorted or completely open
  • There is a poor electrical connection with the exhaust back pressure sensor circuit
  • The tube that runs from the pressure sensor to the exhaust manifold is blocked
  • The PCM may have failed (extremely unlikely)

What are the symptoms of the P0470 code?

The Check Engine Light usually comes on if this code is present. You’ll most likely also feel a lack of power from your engine.

Manual regeneration will be impossible. Eventually, the problem may evolve into a crank-no start too.

How does a mechanic diagnose the P0470 code?

Given how often it’s involved with a code P0470, the first thing a mechanic will do is check the exhaust back pressure sensor when looking to diagnose the underlying problem.

Then they’ll disconnect the tube that connects the exhaust manifold to the exhaust pressure sensor and attempt to run air through it. If that proves impossible, they can use a wire to dislodge whatever may be causing the blockage.

Next, the mechanic will check the wiring involved for signs that it has been compromised. The connectors will also need to be similarly inspected.

The harness that runs to the exhaust pressure sensor can also be disconnected so that the power supply circuit can be tested to ensure it is working properly.

If nothing else seems to work, the issue is most likely that the exhaust pressure sensor is simply malfunctioning.

Common mistakes when diagnosing the P0470 code

The most common problem is just not giving the back pressure sensor the attention it deserves when diagnosing the problem. More often than not, that’s where you’ll find the problem, so start there and check everything before moving on or you may waste a lot of time only to return to the sensor or, even worse, misdiagnosing the problem completely.

How serious is the P0470 code?

The longer the P0470 lasts for, the longer you’re going to be driving a vehicle that isn’t reaching its potential in terms of performance and power. Keep in mind, though, that the sensor could simply be malfunctioning which means it just needs to be replaced but everything else is working fine.

What repairs can fix the P0470 code?

  • As we covered above, the big one is replacing the back pressure sensor. Usually, this is enough to make the code disappear.

  • Otherwise, the sensor and its associated circuits will need to be tested to make sure the former isn’t malfunctioning because of the latter.

  • The power supply for the sensor will also be tested to confirm that’s not the reason why it’s not working correctly.

  • The power supply to the exhaust pressure sensor should also be gauged.

Additional comments for consideration regarding the P0470 code

Usually, this is a pretty quick fix if one of the above issues is to blame. While the symptoms may not seem especially dire, this is still something you should have diagnosed. If the problem causing the P0470 code isn’t one of the above, something far worse could be in the works.

Need help with a P0470 code?

If your vehicle is currently suffering from a problem related to P0470, YourMechanic is ready to help. You can reach one of our service advisors at 1-800-701-6230 or schedule an appointment online. Certified mobile mechanics are standing by and can meet you at your home or office to assess and repair your vehicle. We’ll be sure to give you a free quote before we send them out too.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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