If your car is displaying the P0174 engine code, the O2 sensors are indicating that the air-fuel mixture ratio is too lean. That means your engine is getting too much air and not enough fuel. This can cause your vehicle to burn gas too quickly. It may also lead to other performance problems, so you should get the problem fixed right away.
Diagnostic trouble codes (DTCs) allow you to quickly identify engine problems in your car. Once you scan the code with an OBD-II code reader, understanding the meaning behind the specific code will help you identify the source of your engine trouble and figure out what to do next.
Car insurance
comparison and broker super-app Jerry
is here to help you protect your vehicle by giving you a full breakdown on DTCs and industry-leading savings on car insurance. Here’s everything you need to know about the P0174 engine code, including what it means, how to handle it, and how much it might cost to repair your vehicle.
What does the engine code P0174 mean?
Definition: System Too Lean Bank 2
The P0174 engine code indicates that your car’s air-fuel ratio is too lean. The gas in your car has to be mixed with oxygen before it can combust and power your vehicle. When the air and gas are present in the right ratio (known as the stoichiometric ratio or “stoich”), the mixture burns completely.
However, if the mixture is too lean—meaning there’s too much air and not enough fuel—your vehicle won’t run efficiently.
How much will it cost to fix engine code P0174?
The cost of repair can vary widely depending on what’s causing the P0174 engine code, as well as whether it’s something you can fix yourself or need a mechanic for. If the problem is that your Positive Crankcase Ventilation (PCV) valve
is improperly connected, the fix might be as simple as snapping it back into place. On the other hand, if the problem is a vacuum leak, a professional repair might be $1000 or more.
Here are a few of the causes of a P0174 engine code and how much it costs on average to have a mechanic fix them:
Intake air leak: $550-$600
Faulty front heated O2 sensor: $325-$400
Fuel injector replacement: $600-$750
Exhaust gas leak: $300-$400
PCV valve replacement: $75-$100
Key Takeaway: Because there are so many potential causes for this engine code, a full diagnosis is needed before the cost can be determined.
What can cause the P0174 engine code?
If you’re seeing the P0174 engine code, there’s a problem with the ratio of air and fuel that’s being sent to your engine. Unfortunately, this can have a lot of different causes, from air leaks and fuel injector problems to faulty sensors, so it’s best to take it to a mechanic to have the problem diagnosed professionally.
Too much air in your air-fuel ratio could be caused by an air leak in your car’s intake or exhaust or an incorrect Positive Crankcase Ventilation (PCV) hose connection. Or, it might be caused by a faulty sensor, like a front-heated oxygen (O2) sensor or a Mass Air Flow (MAF) sensor, either of which could interfere with the right amount of air being sent to the engine.
If the problem is that not enough fuel is being sent to the engine, you might have an issue with a faulty fuel injector, or there might be a problem with your fuel pressure. It could also be due to your ignition misfiring
, which can have several causes, from worn-out spark plugs to a vacuum leak. If your car is showing engine codes P0171 and P0174 together, the problem is very likely caused by an intake leak.
Common symptoms of the P0174 engine code
With this engine code, you might not notice any problems other than the Check Engine Light
coming on. However, a lean air-fuel ratio can cause your car to consume excessive amounts of fuel—so you may notice you’re having to refuel your vehicle more often. That said, depending on what’s causing the problem, you may also notice other issues like your car misfiring or stalling.
How serious is the P0174 engine code?
Because you may not notice other vehicle issues right away, you might be tempted to ignore a P0174 code for a while. However, because your engine isn’t getting the right amount of fuel, a problem with the air-fuel mixture can lead to dangerous driveability issues.
It’s very important to get your vehicle checked out by a mechanic as soon as possible.
Furthermore, some of the causes of this issue can come with their own dangerous side effects. For instance, if you have an exhaust leak, you could be exposed to carbon monoxide fumes, which can be deadly.
Can I fix the P0174 engine code myself?
You may be able to fix the P0174 engine code yourself. However, it can be tricky to figure out what’s causing the problem with your air-fuel mixture.
Start by visually inspecting the wiring harness and connectors. Check for anything that’s damaged—especially broken, bent, pushed out, or corroded connector pins.
If nothing is obviously out of order, or if you’re not sure how to fix the problem, bring your car to a mechanic for a thorough diagnostic inspection. From there, you can decide whether the problem is something you can manage on your own. You may need to:
Replace or reconnect your PCV hose connection
If the problem is more extensive, like a leak in your intake or exhaust, it’s probably best to have those repairs done professionally.
Finding insurance for your vehicle
Car repairs can be costly, but with Jerry
, your insurance doesn’t have to be. Jerry is a licensed car insurance broker super-app. In less than two minutes, Jerry can get you quotes from top insurance companies, so you can save big on car insurance
without sacrificing the coverage you need. In fact, Jerry users save an average of $887 a year on car insurance! And the process couldn’t be easier. Jerry collects all of your information from your existing insurer, and they’ll help with all of the paperwork. They’ll even help you cancel your old policy!
“Jerry
found me useful quotes immediately, so I switched over my insurance in under an hour! I’m now helping my parents use Jerry because they just bought a new car.” —Brindi J.
Saved $725 annually
4.7
We value your privacy
