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P2291 Code on 6.7 Powerstroke: Meaning & How To Fix

6.7 Powerstroke engines are considered to be some of the most reliable engines around, but that doesn’t mean they’re without fault. If your Powerstroke is showing a P2291 error code, it’s important to diagnose the problem and find a solution as soon as possible.

A P2291 code on a 6.7 Powerstroke means there’s a problem with the high-pressure fuel injection system. This code typically means the pressure is too low. Common fixes include replacing the pressure control sensor, getting an oil change, fixing an oil leak, and checking for issues with the gaskets.

In this post, I’ll show you what a P2291 code means, its main symptoms, and what you can do to fix the issue.

What Does a P2291 Code on a 6.7 Powerstroke Mean?

A P2291 Code on a 6.7 Powerstroke means there’s not enough injector control pressure. Not only can this problem make the engine have to work much harder, but it can also cause starting issues.

In the long run, a 6.7 Powerstroke engine with injector control problems will need to be replaced. However, fixing the P2291 diagnostic code early on may prevent costly repairs.

What Causes a P2291 Code on a 6.7 Powerstroke?

Car Parts explains that low injection pressure is just as bad as high injection pressure. A 6.7 Powerstroke is designed to produce a higher injector control pressure than many vehicles, but it can get too high for the engine to handle. The wrong injection pressure can result in leaks and many other issues, such as the P2291 Code.

Thankfully, leaks aren’t typically caused by the P2291 code. Instead, the P2291 code appears when an oil leak is already an issue. Broken gaskets and broken pressure regulator valves can also cause the P2291 code.

If your check engine line keeps showing up without any issues, reset it and see if the P2291 code comes back. The code can also be caused by damaged sensors.

The following are some of the potential reasons your 6.7 Powerstroke shows a P2291 error code:

  • There’s a rusted, corroded, or punctured pipe. Holes in the oil pipes and hoses will leak a lot of oil. When there’s not enough oil, the engine loses a lot of pressure, signaling the P2291 code. Additionally, sizeable leaks let air into the engine, which can reduce the oil’s ability to lubricate and cool it.
  • One of the oil gaskets is loose, worn, or broken. Like the leak issues mentioned earlier, a loose O-ring or gasket will let air into the system. It’ll also reduce the oil pressure, causing the code to appear. The good news is that these are some of the easiest issues to fix because you don’t have to get a new sensor.
  • The pressure regulator valve is malfunctioning. This valve controls how much pressure is being used. When the valve breaks or doesn’t work properly, it’ll cause a dramatic pressure reduction. The valve can create a sudden leak that loses a lot of oil without letting nearly enough of it get to the engine.
  • There is a sensor malfunction. In some cases, the P2291 code might show up by mistake (this is rare, but it happens). It could be caused by a sensor malfunction, but it could also mean there’s something wrong with the diagnostics tool. Resetting the tool and the check engine light will help you find out if there’s an actual problem. These codes are usually combined with many symptoms.
  • You’ve used the wrong type of oil. Not only will the wrong oil clump and coagulate, but it can also severely damage the engine. The result is a P2291 code display followed by an overheated engine, clogged oil filters, and many other problems. Always use the oil recommended by the manufacturer.

Leaks and exhaust problems are also fairly common with P132B codes, so it’s worth testing both codes on your diagnostics tool. However, some of these codes aren’t always easy to spot. 

Head to the next section to learn more about the signs and symptoms that something might be wrong with your 6.7 Powerstroke engine’s high-pressure fuel injection system.

Symptoms of a P2291 Code on a 6.7 Powerstroke

Most symptoms of a P2291 code on a 6.7 Powerstroke are related to starting the engine. For example, you’ll notice the engine has a hard time starting. It’ll crank and try to turn over multiple times before it works. In severe cases, your 6.7 Powerstroke might not even ignite if the injector pressure is low enough.

Here’s a look at all of the symptoms you might encounter:

  • Engine cranks before starting: You may be dealing with a P2231 code if your engine would crank before starting. You might mistake this issue for a faulty battery, especially if it takes a while to turn over. However, this issue occurs when the oil pressure is low enough to prevent it from lubricating the engine. It can also affect how efficiently the engine uses its fuel.
  • Overheating: Oil’s primary purpose is to cool and lubricate numerous metal parts that cause a lot of friction. When there’s not enough oil injection pressure in a 6.7 Powerstroke engine, there’s a very high chance it’ll overheat and damage the block. It’s a very common symptom of a P2291 code.
  • Loud noises, especially when you’re accelerating: If your engine suddenly sounds much louder or like it has to work a lot harder, it’ll likely show an error code soon enough. Furthermore, a P2291 code often includes clunky driving issues as a primary symptom that you should look out for.
  • White smoke comes out of the exhaust pipe: This symptom is often combined with the previously explained overheating concerns, and it should be dealt with immediately. Check your exhaust pipe for corrosion. It tears through the pipe because there’s not enough oil to cool the engine, which sends far too much hot smoke through the exhaust.
  • Sudden loss of power while driving: If your vehicle shows a P2291 code, there’s a chance that you might not be able to drive it at all. Unfortunately, this can happen when you’re in the middle of the road or before you start the vehicle. There’s no way to predict when you won’t be able to drive once the code appears.

All of these symptoms can happen out of nowhere, which can be quite scary and frustrating. However, you might also notice your check engine light illuminates.

If you use a diagnostics tool and it shows the aforementioned P2291 code, pull over to the side of the road and review the repairs and solutions listed below.

How To Fix a P2291 Code on a 6.7 Powerstroke

The P2291 Code relates to most high-pressure diesel engines, including the 6.7 Powerstroke. While it can happen to some gasoline engines, the solutions listed below are geared toward a Powerstroke engine.

  1. Patch or replace any hose with an oil leak. Since this is the most common reason for the P2291 code, it should be the first thing you do. Inspect each hose, looking for oil dripping from small fractures and holes. You can patch them with epoxy, but it’s best to replace the part since epoxy typically doesn’t work as a permanent fix.
  2. Replace the pressure control sensor. A damaged sensor will make your high-pressure injection system think there’s more or less oil than there actually is. This causes it to reduce the oil pressure, which triggers the P2291 code. Replacing the sensor fixes the problem immediately.
  3. Get an oil change if it’s dirty or old (or the wrong type of oil). Changing the oil will regulate the pressure injection system, prevent your engine from overheating, and more. Change the oil, reset the check engine light (if applicable), then test it again with the diagnostics tool. If that doesn’t work, head to the next step.
  4. According to Your Mechanic, you should check the oil injector control regulator. This part works hand in hand with the pressure control sensor to ensure your engine gets the right amount of oil. When the regulator locks or rusts, it can’t keep the pressure high enough. You’ll likely need a mechanic for this repair if you want a warranty.
  5. Inspect each of the gaskets and make sure they’re snug and in good condition. Replace any worn or broken gaskets to seal the oil injection lines, then reset and test them with the diagnostics tool. These gaskets wear down with high-mileage 6.7 Powerstroke engines, especially when they heat up.

If all else fails, test each of the fuses with a multimeter and replace them if needed. You should also tighten each of the wires to ensure there’s no electrical arcing, then replace any wires that have exposed copper.

Final Thoughts

Getting a new error code on your 6.7 Powerstroke can be nerve-racking, but there are many ways to fix the P2291 code.

When left unchecked, this code can lead to overheating and many other unwanted problems. However, keeping an eye out for the aforementioned symptoms will help you stay prepared.