The 2023 Toyota RAV4 triggering P0174 indicates a lean condition on bank 2—too much air relative to fuel on that cylinder bank. For RAV4 models equipped with V6 engines, this points to bank-specific issues requiring diagnosis.
Understanding P0174
P0174 is similar to P0171 but affects bank 2 instead of bank 1. Long-term fuel trim on bank 2 exceeds approximately +25%, indicating the ECM consistently adds fuel to compensate for lean conditions affecting those cylinders.
RAV4 Engine Options
The 2023 RAV4 offers 2.5-liter four-cylinder and hybrid variants. For four-cylinder models, only P0171 applies (single bank). P0174 specifically affects V6-equipped models or may appear alongside P0171 on four-cylinder models with system-wide issues.
Bank 2 Specific Causes
Vacuum leaks affecting bank 2 cylinders. Fuel injector issues on bank 2 cylinders. Exhaust leak before bank 2 oxygen sensor. Secondary air injection issues if equipped.
Vacuum Leak Detection
Vacuum leaks are the most common lean cause. Check intake manifold gaskets, particularly sections serving bank 2 cylinders. Inspect vacuum hoses routed near bank 2. Smoke testing identifies leak locations.
Fuel Delivery Issues
Weak fuel injectors on bank 2 cylinders can cause bank-specific lean conditions. Test individual injector operation. Compare fuel trim between banks to identify patterns.
Repair Costs
Vacuum hose replacement costs $50-200. Intake gasket replacement runs $300-600. Fuel injector replacement ranges $200-400 per injector.