2007-2021 Toyota Tundra
P0171
System Too Lean (Bank 1) - Toyota Tundra
The Tundra's 5.7L 3UR-FE and 4.6L 1UR-FE develop MAF contamination and aging PCV valves - both produce Bank 1 lean codes past 100k miles
Moderate Severity $10-$320 Typical Repair Try Cleaning MAF First
Plain English

What P0171 means for your Tundra

Your Tundra is running lean on Bank 1. On Toyota Tundras with the 5.7L 3UR-FE or 4.6L 1UR-FE V8, the dominant P0171 cause is a carbon-coated MAF sensor that underreports airflow. A $10 can of MAF cleaner resolves it most of the time. Second most common is a failing PCV valve on the UR-series V8 - it sticks open and creates an unmetered vacuum leak. Cracked intake hoses are a distant third.

🎯 Top Causes on the Toyota Tundra

45%
#1 CAUSE
Contaminated MAF Sensor
The UR-series V8 MAF sensor accumulates fine carbon and PCV oil mist after 80k-120k miles. Cleaning with CRC MAF cleaner restores accurate airflow reporting. This is a 10-minute DIY job and the cheapest possible fix. Do not use anything other than MAF-specific cleaner.
MAF Cleaner
$8-$15 DIY
Labor
$0 DIY
Total
$8-$50
30%
#2 CAUSE
PCV Valve Stuck Open (UR V8)
The PCV valve on the 5.7L 3UR-FE and 4.6L 1UR-FE V8 sticks open after high mileage, creating a constant unmetered vacuum leak. The valve is on the valve cover. Replacement is a Toyota OEM PCV - around $30-$50 part, 15 minutes labor.
PCV Valve
$30-$50
Labor
$40-$80
Total
$30-$130
25%
#3 CAUSE
Cracked Intake Hose / Snorkel
The rubber intake snorkel cracks at the bellows section, especially in hot climates. A visible crack or smoke test confirms it. Toyota OEM hose replacement is the recommended fix.
OEM Hose
$120-$200
Labor
$40-$80
Total
$160-$280

🚚 Most Affected Tundra Model Years

YearEngineTrimTypical MileageNotes
2007-20215.7L 3UR-FE V8SR5, Limited, Platinum, 179490k-170kMAF and PCV valve dominant
2010-20194.6L 1UR-FE V8SR, SR5100k-180kSame MAF and PCV pattern as 5.7L
2007-20094.7L 2UZ-FE V8SR5120k+Older V8; intake hose cracks more common

⚠ Is It Safe to Drive Your Tundra with P0171?

Yes - safe to drive normally; address within a month.

P0171 on the Tundra is a maintenance issue, not an emergency. Try the MAF cleaning first. If you tow heavy loads regularly, address the leak sooner - lean conditions stress catalysts and reduce power.

🔧 How to Diagnose P0171 on a Toyota Tundra

  • Clean the MAF sensor. Remove the MAF, spray with CRC MAF cleaner, let dry, reinstall. Clear codes and drive 15-20 minutes. Recheck LTFT. This alone resolves roughly half of all Tundra P0171 cases.
  • Inspect and test the PCV valve. Unscrew the PCV valve from the valve cover. A good valve rattles when shaken. A stuck-open valve has no movement and pulls a constant unmetered air signal. Replace with Toyota OEM.
  • Smoke-test the intake. If MAF and PCV are clean and functional, smoke-test the intake snorkel and any vacuum hoses. Look for visible smoke at hose joints and the snorkel bellows.
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❓ P0171 Toyota Tundra FAQs

How much does P0171 cost to fix on a Toyota Tundra?

MAF clean: $8-$50. PCV valve: $30-$130. Intake hose: $160-$280. Most cases fix under $130.

Does the Tundra 5.7L have any known recalls for P0171?

No P0171-specific recall, but Toyota issued service bulletins on the UR-series PCV valve. Ask the dealer to check your VIN.

Will P0171 affect Tundra towing?

It can reduce peak power and stresses the catalyst under sustained tow load. Fix before extensive towing.

Can I use a generic MAF cleaner?

Use only MAF-specific cleaner (CRC MAF, Wurth MAF cleaner). Generic carb or throttle body cleaner can damage the sensing wires.

See all P0171 causes and vehicles ->

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