OBD codes / P0152
P0152
ModerateO2 Sensor Circuit High Voltage (Bank 2, Sensor 1)
Drivable short-term, but do not just clear it and forget it: if Bank 2 is genuinely rich, every mile washes fuel past that bank's rings and toward its catalytic converter. If you notice fuel smell, black smoke, or a rough idle alongside this code, move diagnosis up the priority list.
What this code means
P0152 means the upstream oxygen sensor on Bank 2 — the fuel-control sensor for the cylinder bank opposite cylinder 1, present only on V-type and flat engines — is sending a signal stuck high, i.e., reporting rich continuously. Two families of cause exist. Electrical: a failing sensor, a contaminated element, or a signal wire shorted to a voltage source. Real: Bank 2 genuinely running rich, from a leaking injector on that bank, excessive fuel pressure, or a fuel-soaked evaporative-purge problem. The distinction is worth a proper look, because a genuinely rich bank wastes fuel, can foul that bank's spark plugs, and can overheat its catalytic converter — problems a new sensor will not touch. As a fuel-control sensor fault, expect some economy loss while the code is active.
Symptoms you might notice
- Check-engine light
- Worse fuel economy
- Fuel smell or dark exhaust if the bank is genuinely rich
- Rough idle or fouled plugs on one bank in stronger cases
- Failed emissions test
What it costs to fix
Typical range: $150–$600 · about ~0.3–1.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Upstream oxygen (O2) sensor | $50–$250 | ~0.3–1.5 hrs |
| Wiring / connector repair | $10–$120 | ~0.5–1.5 hrs |
| Exhaust leak repair near the sensor | $20–$200 | ~0.5–2 hrs |
If the sensor is at fault, cost tracks any upstream sensor job, with Bank 2 access on transverse engines the usual labor multiplier. If diagnosis finds a genuinely rich bank — an injector or fuel-pressure issue — the repair belongs to that system and may exceed these figures.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0152 for my exact vehicle →
Frequently asked
What does high voltage from an upstream O2 sensor mean?
The signal is pinned at the rich end. Either Bank 2 really is running rich — leaking injector, high fuel pressure — or the signal is false: a worn/contaminated sensor or a wire shorted to voltage. Fuel-trim data tells the two apart.
Is it safe to drive with P0152?
For short-term normal driving, yes. The risk of waiting is mostly if the bank is genuinely rich — excess fuel can foul plugs and overheat the catalytic converter over time — so aim for diagnosis within days or a few weeks, not months.
P0152 versus P0172 — what's the difference?
P0152 says the Bank 2 upstream sensor's signal is stuck high; P0172-family codes say the computer concluded a bank is actually running rich. Seeing both together strengthens the case for a real mixture problem rather than a bad sensor.
Why did a new sensor not fix my P0152?
Because the sensor was probably reporting the truth. A genuinely rich Bank 2 — from an injector, fuel-pressure, or purge-valve problem — or a harness shorted to voltage will pin the new sensor's signal exactly like the old one.
Seeing P0152 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0152 for my vehicleRelated trouble codes
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.