p0174
Moderate
Toyota · SUVs
System Too Lean Bank 2
Quick Answer
Error code P0174 on your Toyota SUVs means: System Too Lean Bank 2. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Vacuum leak on the Bank 2 side of the intake manifold (V6 engines)
  2. Faulty mass airflow sensor underreporting airflow
  3. Clogged fuel injectors on Bank 2 cylinders
  4. Cracked intake runner or plenum gasket leak on Bank 2 side
  5. Faulty PCV valve causing excess unmetered air
How to Fix It
1
Inspect the Bank 2 side of the intake manifold for vacuum leaks using a smoke machine
2
Clean or replace the MAF sensor and verify fuel trims normalize
3
Test fuel injectors on Bank 2 cylinders for flow rate and spray pattern
4
Inspect the PCV valve and hose for proper operation
5
Check the intake plenum gasket for leaks, especially on V6 models
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
MAF sensor
Intake manifold gasket set
Fuel injectors
PCV valve
Related Error Codes
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