Parts
$15–80 sensor / $25–200 injector / varies by root cause
P0175 — System Too Rich — Bank 2
SAFEIs it safe to drive? Safe to drive short-term but running rich fouls spark plugs, shortens catalytic converter life, and dilutes engine oil with fuel — fix within a week.
What P0175 means
Long-term fuel trim on Bank 2 has gone negative beyond the threshold (typically more negative than -10%), meaning the ECU is pulling fuel but the engine is still running rich. This is the Bank 2 counterpart to P0172.
Most likely causes (in order)
- Leaking fuel injector(s) on Bank 2 dripping fuel when closed
- Faulty Bank 2 upstream O2 sensor stuck in rich position
- High fuel pressure — failing fuel pressure regulator
- Mass airflow sensor reading low (causes all banks to run rich — check for P0101/P0102)
- Stuck-open EGR valve or coolant temperature sensor fault causing excess fueling
Symptoms you might notice
- Fuel smell from exhaust
- Poor fuel economy
- Rough idle
- Spark plugs fouling on Bank 2 side
- Oil may smell like fuel if running very rich
What to check first
Check Bank 2 long-term fuel trim live; if it's more negative than -10%, the bank is definitely rich. Compare Bank 1 and Bank 2 trims — if both are negative, the cause is global (MAF sensor, high fuel pressure, coolant temp sensor). If only Bank 2 is negative, suspect a leaking injector or a Bank 2-specific O2 or coolant sensor fault. Listen for a ticking injector that stays open at idle.
Repair cost & difficulty
Labor
0.5–2.0 hr
Difficulty
Moderate