P0174 on a Toyota Tacoma
P0174 means system Too Lean (Bank 2). On the Tacoma, a few causes come up far more than others.
What P0174 usually means on a Tacoma
P0174 is the bank 2 lean code and shows up only on V6 Tacomas. It means the second cylinder bank is running lean. On its own it usually points to a vacuum leak specific to that bank, such as a cracked PCV line or leaking intake gasket. When it comes with P0171, the cause is generally shared between banks — a dirty MAF or low fuel pressure.
Most common causes on the Tacoma
- Bank 2 vacuum leak
A cracked hose or leaking gasket on the second bank leans only that side.
- Dirty MAF (with P0171)
If both banks go lean together, a dirty MAF is the common denominator.
- Failing bank 2 AF sensor
The rear bank's Denso sensor is frequently the original unit and slows down over time.
- Low fuel pressure
A failing pump leans both banks under load, so measure fuel pressure if trims rise across the board.
What P0174 costs to fix on a Tacoma
A standalone P0174 usually means hunting a bank 2 vacuum leak, which takes diagnostic time on the V6. A cause shared with P0171 is easier to isolate. A smoke test is the fastest route to the leak.
Year, engine and mileage change the answer. Start a case and Redline weighs these causes against what your car shows, then names the check that would settle it.
Other codes on the Toyota Tacoma
Related symptoms
Toyota Tacoma problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0174 behavior is covered on the main P0174 page. Confirm with a scan tool before buying parts.
P0174 on your Tacoma?
Every problem becomes a Case. Tell Redline what your Tacoma is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.