OBD codes / P0174 / Toyota Camry
P0174 on a Toyota Camry
System Too Lean (Bank 2)
3.5L 2GR-FE V6 only; bank 2 is the firewall side.
What P0174 usually means on a Camry
P0174 is the bank 2 counterpart to P0171 and only appears on V6 Camrys. It means the rear cylinder bank is running lean. When P0174 shows up alone, suspect something specific to that bank — a rear intake gasket, a cracked PCV line, or a lazy bank 2 air-fuel sensor. When it pairs with P0171, the cause is usually shared, like a dirty MAF or weak fuel pressure feeding both banks.
Most likely causes on this model
- Bank 2 vacuum leak
A cracked rear PCV hose or leaking rear intake gasket leans only the firewall-side bank.
- Dirty MAF sensor (with P0171)
If both banks read lean, a contaminated MAF is the common denominator.
- Failing bank 2 AF sensor
The rear Denso sensor is original on many V6s and slows with age.
- Low fuel pressure
A weak pump pushes both banks lean under load, so check pressure if trims climb everywhere.
What it costs on a Camry
If P0174 stands alone, budget for chasing a rear-bank vacuum leak, which is fiddly because the hoses tuck behind the intake. A shared cause with P0171, like a MAF or fuel pump, is usually cheaper to pin down. Smoke-testing the intake is the fastest way in.
Year, engine and mileage change the answer. Get a diagnosis for your Camry — it weighs these causes against your exact configuration and real complaint data.
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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.