Diagnostic codes on massive and complicated engines like the 7.3L Powerstroke are lifesavers – they help us identify issues before they damage the engine any further. It’s invariably a good idea to clear a diagnostic code as soon as you notice the signs of a fault.
A P0470 code on a 7.3L Powerstroke means there’s an issue with the exhaust back pressure sensor. It points to a fault with the sensor or the system powering the sensor. Symptoms like high consumption, rough idling, and reduced power accompany the P0470 code.
This piece will delve deeper into the causes, symptoms, and fixes of the P0470 code on a 7.3L Powerstroke.
What Does a P0470 Code on a 7.3L Powerstroke Mean?
A P0470 code on a 7.3L Powerstroke engine—and all Ford engines with variable-geometry turbochargers—indicates an issue with the exhaust back pressure sensor (EBPS) or the system that runs the sensor.
The EBPS reads exhaust back pressure, allowing the PCM to alter the position of the exhaust back pressure valve.
An issue with the EBPS affects the normal functioning of the engine.
Symptoms Accompanying a P0470 Code on a 7.3L Powerstroke
A P0470 code can manifest itself in the following ways.
- Check Engine Light
- Higher Consumption
- Reduced Power
- Rough Idle
Check Engine Light
An illuminated check engine light can be the first sign of a faulty EBPS or EBPS system. The check engine light can point to a multitude of issues, so you need a mechanic or a diagnostic tool to isolate the problem.
You should fix the P0470 code as soon as possible before the fault causes other symptoms or damages other parts of the motor.
Higher Consumption
Faulty readings from a malfunctioning EBPS can cause the engine to consume more than it should. For instance, a short in the sensor wiring can send a low voltage reading to the PCM, prompting it to position the EBPV in the default position.
The vehicle’s consumption increases due to compromised engine function.
Reduced Power
Your vehicle can consume more fuel while producing less power due to a faulty EBPS or EBPS system. For instance, if the EBPS incorrectly reads that the exhaust back pressure has surpassed safe levels, the PCM will reduce turbo boost, open the EBPV, and limit fuel flow to the engine.
Consequently, you’ll feel random drops in power caused by an erroneous EBPS reading.
Rough Idle
Many issues can cause idling, including problems relating to the P0470 code. The roughness can also appear during acceleration.
Eventually, the vehicle can refuse to start due to insufficient diesel particulate filter regeneration. Exhaust back pressure affects regeneration – the clearing of soot from the particulate filter.
A compromised EBPS can slow the regeneration process, clogging the diesel particulate filter (DPL). A 7.3L Powerstroke with a clogged DPL won’t start.
Causes of the P0470 Code on a 7.3L Powerstroke
A closer look at the causes of the P0470 code will help you better understand how to deal with the issue.
- Clogged or Leaking Tubes
- A Faulty Sensor
- Electrical Problems
- A Faulty PCM
Clogged or Leaking Tubes
Clogged or leaking tubes in the exhaust system can cause faulty EBPS readings, leading to the P0470 error code.
The most common culprit is the EBP tube, which clogs up with soot over time. The tube runs from the exhaust pressure sensor to the exhaust manifold.
A Faulty Sensor
The EBPS can wear out with time or break under impact, prompting the PCM to throw up the P0470 code.
Sometimes, sensor damage happens during installation. Installing a new sensor soon after replacing it can be hugely frustrating and unnecessarily expensive, so pay close attention to the sensor replacement process described further below.
Electrical Problems
A wiring issue can affect the functioning of the EBPS, leading to the emergence of the P0470 code.
Electrical problems connected to the P0470 code often point to a short or open harness or a poor electrical connection with the EBPS.
A Faulty PCM
In isolated cases, the vehicle’s PCM might be the issue. The PCM is essentially the car’s processing unit, so if it goes haywire, it might produce codes even when there’s no fault.
How To Fix a P0470 Code on a 7.3L Powerstroke
Thankfully, fixing a P0470 code issue isn’t complicated. With the right equipment, you can clear the problem from your home garage.
1. Unclog Tubes, Seal Leaks, and Clean Connectors
The first step involves rectifying problems caused by the everyday running of the engine. It’s almost inevitable that the EBP tube on a 7.3L Powerstroke will clog up with soot.
Locate the EBPS on the engine right in front of the high-pressure oil pump. The EBPS tube runs from the EBPS to the exhaust manifold on the vehicle’s passenger side.
Disconnect the tube from the manifold and attempt to force compressed air through it. If the air fails to pass through, the blockage was likely the cause of the P0470 code. Use a piece of wire to dislodge the soot blocking the EBP tube.
You can use a solvent to clean the EBP tube, but ensure to keep the EBPS free from chemicals. After cleaning, use compressed air to remove moisture and any lingering dirt.
Sometimes, the EBP tube rusts and corrodes so much that it breaks into two. The car rides very rough while producing the P0470 code. Therefore, keep a close eye on the EBP tube, especially on a 7.3L Powerstroke running beyond 200,000 miles (321,868.8 kilometers).
Afterward, look for leaks in the connections around the intake manifold and turbocharger. Seal any leaks you find and tighten all clamps.
Finally, dislodge the connectors and look for signs of corrosion. Clean the terminals using Electrical Contact cleaner or rubbing alcohol and a light bristle brush.
Restore the connectors before erasing all error codes using a scan tool. If the P0470 code doesn’t return, you’ve resolved the issue; if it shows up, move to the next step.
2. Fix Electrical Problems
An electrical problem might be the cause of the P0470 error. Check for electrical issues in the following areas:
- Harness: Disconnect the EBPS harness and use an OhmMeter to test the voltage traveling to the sensor. Any reading other than 5V points to a wiring issue. Replace the wiring and retest the voltage before reconnecting the harness.
- EBPS signal circuit: Next, use the OhmMeter to check whether 5V are passing to the EBPS signal circuit. Repair the wiring if the OhmMeter reads anything other than five volts.
- EBPS ground: The last place to check is the EBPS ground. Connect a test light to a battery positive and the other end to the ground circuit connecting to the EBPS circuit ground. The test light should light up if there’s no issue. If it doesn’t, replace the ground wiring and test to see if it works properly.
After fixing any electrical issues, clear code memory using a diagnostic tool. If the P0470 code returns, move to the next step.
3. Replace the EBPS
If the steps above fail, the next step involves replacing the EBPS. At this point, the EBPS is the most probable cause of the P0470 code, but you can test the device to confirm that it is faulty.
Test the EBPS using this process:
- Disconnect the battery by removing the negative terminus.
- Remove the air intake hose to access the EBPS.
- Check the continuity between the wires using a multimeter.
- If there’s no continuity, the EBPS is broken.
You can also test the EBPS by checking the resistance of the sensor. The resistance figure on the OhmMeter should range from 700 to 1200 ohms. Any reading outside this range points to a faulty sensor.
You can attempt to clean the EBPS using a solvent like brake cleaner. It could work, but cleaning a faulty EBPS is only a temporary fix. If the EBPS is broken, you’ll have to replace it.
Replace the EBPS by following these steps:
- Access the EBPS at the front of the engine by removing the plastic cover.
- Dislodge the electrical connector carefully. Take extra care if the 7.3L Powerstroke has run many miles, as the engine heat reduces the robustness of plastic connectors and harnesses.
- Remove the sensor while holding the nut beneath the bracket. Failure to support the bracket may damage or bend it.
- Pour some PB Blaster on the ends of the EBP tube before attempting to remove the nuts connecting it to the sensor and the exhaust manifold. Once the nuts loosen, remove the tube.
- After clearing the tube, reinstall it starting with the sensor bracket side.
- Carefully install the new sensor to avoid puncturing the sensor’s diaphragm.
- Reinstall the connector.
After replacing the EBPS, clear the error code using a diagnostic tool. If the error returns move to the next step.
4. Replace the PCM
If the P0470 code persists, your 7.3L Powerstroke likely has PCM issues. PCM problems are rare on 7.3L Powerstrokes, but it could be the last remaining explanation.
Seek professional help if you suspect a PCM problem.
Final Thoughts
The P0470 code on a 7.3L Powerstroke engine points to issues with the EBPS. The EBPS is a hardy sensor lasting hundreds of thousands of miles.
If the P0470 code forces you to replace the EBPS, you can install aftermarket options that last even longer. If you suspect a fuel pump issue on your 7.3L Powerstroke, refer to the following article to diagnose the problem.