P0174 Toyota Code - Fuel Trim System Too Lean Bank 2
Quick Answer
When the OBD-II code P0174 appears on a Toyota vehicle, it indicates that the fuel trim system on bank 2 is detecting a lean condition. Common causes include Vacuum leaks in the intake system, Faulty Mass Air Flow (MAF) sensor, Clogged fuel injectors. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0174 Toyota indicates Fuel Trim System Too Lean Bank 2.
- Common causes
- Common causes include Vacuum leaks in the intake system, Faulty Mass Air Flow (MAF) sensor, Clogged fuel injectors.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P0174 Toyota Description
When the OBD-II code P0174 appears on a Toyota vehicle, it indicates that the fuel trim system on bank 2 is detecting a lean condition. This means that the engine is receiving too much air and not enough fuel, leading to an imbalance in the air-fuel mixture. The Engine Control Module (ECM) is unable to correct this issue, causing the fuel trim to exceed the specified limits. This can result in poor fuel economy, reduced engine performance, and potential damage to the catalytic converter over time.
Common Causes of P0174 Toyota
- Vacuum leaks in the intake system
- Faulty Mass Air Flow (MAF) sensor
- Clogged fuel injectors
- Fuel pump malfunction
- Exhaust leaks near the oxygen sensors
Symptoms of P0174 Toyota
- Check Engine Light is illuminated
- Reduced engine power
- Hesitation or stalling during acceleration
- Rough idling or misfires
- Increased fuel consumption
How to Fix P0174 Toyota
- Perform a visual inspection of the intake system and vacuum lines for any leaks. Repair or replace damaged components.
- Test the Mass Air Flow (MAF) sensor using a multimeter and replace if faulty.
- Clean or replace clogged fuel injectors.
- Check fuel pressure from the fuel pump and replace if necessary.
- Inspect the exhaust system for leaks near the oxygen sensors and repair as needed.
Cost to Fix P0174 Toyota
The cost of repairing the P0174 code on a Toyota vehicle can vary depending on the specific cause of the issue. On average, expect to pay between $200 and $600 for parts and labor. Keep in mind that diagnostic time and labor rates can fluctuate based on location and the shop's hourly rates. It's recommended to get a detailed estimate from a trusted mechanic before proceeding with the repair.
Tech Notes for P0174 Toyota
There is a factory service bulletin for the following Toyota models:
2005 – 2007 Toyota Avalon
2007 – 2008 Toyota Camry
2005-2007 Toyota Avalon, 2007-2008 Toyota Camry Factory Service Bulletin OBDII Code P0174
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Information for Specific Toyota Models
- P0174 2006 Toyota Camry — Air/Fuel Mixture System Too Lean Bank 2
- P0174 2007 Toyota Camry — Air/Fuel Mixture System Too Lean Bank 2
- P0174 2008 Toyota Camry — Air/Fuel Mixture System Too Lean Bank 2
- P0174 2009 Toyota Camry — Air/Fuel Mixture System Too Lean Bank 2
- P0174 2010 Toyota Camry — Air/Fuel Mixture System Too Lean Bank 2
- P0174 2011 Toyota Camry — Air/Fuel Mixture System Too Lean Bank 2
- P0174 2013 Toyota RAV4 — Fuel Trim System Too Lean Bank 2
- P0174 2014 Toyota RAV4 — Fuel Trim System Too Lean Bank 2
- P0174 2015 Toyota RAV4 — Fuel Trim System Too Lean Bank 2
- P0174 2016 Toyota RAV4 — Fuel Trim System Too Lean Bank 2
- P0174 2017 Toyota RAV4 — Fuel Trim System Too Lean Bank 2
- P0174 2018 Toyota RAV4 — Fuel Trim System Too Lean Bank 2
Frequently Asked Questions about P0174 Toyota Code
1. What are common symptoms of OBDII code P0174 (Fuel Trim System Too Lean Bank 2) in a Toyota?
- Common symptoms include rough idling, poor acceleration, decreased fuel efficiency, and potential stalling.
2. What are the possible causes of OBDII code P0174 in a Toyota?
- Possible causes include a vacuum leak, faulty oxygen sensor, clogged fuel injectors, fuel pump issues, or a dirty air filter.
3. How can I diagnose the cause of OBDII code P0174 in my Toyota?
- Diagnose by checking for vacuum leaks, inspecting the oxygen sensor, cleaning or replacing the air filter, testing fuel injectors, and ensuring proper fuel pressure.
4. Can a clogged fuel filter trigger OBDII code P0174 in a Toyota?
- Yes, a clogged fuel filter can restrict fuel flow, leading to a lean condition and triggering code P0174 in the fuel trim system.
5. Is driving with OBDII code P0174 in a Toyota safe?
- Continuing to drive with code P0174 may cause damage to the engine and other components over time, so it is recommended to address the issue promptly.
6. How can I reset OBDII code P0174 in my Toyota after making repairs?
- Reset the code using an OBDII scanner or by disconnecting the car's battery for a few minutes. Note that the code may reappear if the underlying issue is not fixed.
7. Can a faulty mass airflow sensor (MAF) cause OBDII code P0174 in a Toyota?
- Yes, a malfunctioning MAF sensor can disrupt the air-to-fuel ratio and lead to a lean condition, triggering code P0174 in the fuel trim system.
8. What are some general repair tips for addressing OBDII code P0174 in a Toyota?
- Inspect and replace worn-out components, perform regular maintenance, use high-quality fuel, and address any issues promptly to prevent code recurrence.
9. How can a professional mechanic help diagnose and repair OBDII code P0174 in a Toyota?
- A mechanic can conduct advanced diagnostics, perform thorough inspections, utilize specialized tools, and provide expert guidance on resolving the issue effectively.
10. Are there any preventive measures to avoid OBDII code P0174 in a Toyota?
- Regularly maintain the vehicle, address any warning signs promptly, use quality fuel, and conduct routine inspections to prevent issues that may trigger code P0174.
Discuss the causes and fixes for P0174 Toyota OBDII Code
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Replaced the Air fuel sensor with 3 different sensors
I get the same code
"P0174
System too lean
Bank 2" -
What model and year is your vehicle? Are there any intake or exhaust leaks?
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I have a 2002 Toyota Avensis (T22) 1.8 VVTi and I got fault codes P0171 and P0174. It was quite cold (-27C/-16.6F) this morning when the codes popped up. I wonder if it was the cold air that made the fault codes happen.
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i have FJ 2007 and i replace the exhuast to performance exhaust after that i have p0174 syestm too leen .. what is the problem?
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Probably the aftermarket performance exhaust does not meet the the factory requirements to work on your vehicle.You may have to contact the performance exhaust manufacture for more information.
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I get p0171 and p0174 on my sienna 2002 xle. Should the logical approach to correct the issue are
1. Change the air and gas filters
2. Change the oxgyen sensor -
1. Check for Intake air leaks
2. Clean Mass Air Flow Sensor (MAF)
3. Change the air and gas filters
4. Change the oxygen sensor -
I have this issue. Spark plugs changed, clean Mass Air Flow. Air filter isnt dirty. Just a few leaves was in it. There were no leaks from smoke test. Car shakes at idle like it wants to shut off.
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If cleaning the the Mass Air Flow (MAF) didn't fixed the problem, then you may have to replace it.
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I went back to have them check the code again and not the #2 is misfiring so i think its either the spark plug not tight enough or the coil. It wasnt misfiring before.
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I have P0171 and P0174 on my 2003 toyota rav 4, what are the logical steps to follow to get rif of the codes?
Thanks for any and alll help rendered. -
Start by cleaning or replacing the air filter and any debris in the air filter box and check for any loose or broken intake hose. If the codes come back, the next step is to clean the Mass Air Flow (MAF) sensor. If the code comes back again, then you have to replace the MAF. The MAF is by far the most common component that will set the P0171 and P0174 codes.
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I have P0174, P0300 and P0302 on my 2005 4 runner. I know I need to replace my front passenger cat converter. Could these be the cause of the codes? Or the cheap gas I got from the country gas station?
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Yes, low octane gas could set those codes. Also, before replacing the Catalytic Converter, you should start by replacing the spark plugs.
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02 Solara v6 3.0 SLE Convertible p0171, p0174 and VERY hard brake pedal.... sounding like a vacuum leak. I am in NO WAY a mechanic but can follow directions and have been successful fixing several issues (not this car thankfully-first issue on Toyota). Is there a BASIC video somewhere showing where to look for leaks. Considering taking to BrakeMasters but I just know I'm going to be told I need a new Booster or MAF and charged crazy for it when it sounds like it could very likely be a line or hose. Thank you in advance for your help and this awesome resource!!
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You’re on the right track — those lean codes (P0171 and P0174) along with a hard brake pedal almost always point to a vacuum leak, and on that Solara V6 the brake booster hose is one of the first things to check. A split or loose hose at the booster or intake can let in unmetered air and cause both the lean condition and a stiff pedal.
With the engine off, follow the large vacuum hose from the brake booster (the round black can behind the master cylinder) to where it connects to the intake manifold. Look for cracks, loose fittings, or a broken check valve. If everything looks good, spray a little carb cleaner or brake cleaner around the intake and vacuum hoses while the engine idles—if the idle changes, you’ve found the leak.
It’s a very common and fairly simple DIY fix if it’s just a hose. Replacing the booster itself is more work, but most of the time it’s the hose or check valve causing the problem.
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