P0153 — O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
Drive with caution — fix soon.
What P0153 means
This code means the front oxygen sensor on bank 2 is reporting a persistently high voltage, which the computer reads as a constantly rich exhaust. It can be caused by a failing O2 sensor, a wiring short to power, or an actual rich-running condition from fuel system issues. It's a fairly common code and is usually fixable once the cause of the high reading is pinpointed.
Common symptoms
- Check engine light is on
- Rough idle or slight engine shaking
- Reduced fuel economy
- Black smoke or strong fuel smell from the exhaust
- Possible rich-condition codes stored alongside it
Common causes
- Failing oxygen sensor (Bank 2 Sensor 1)
- Sensor signal wire shorted to voltage
- Leaking fuel injector causing a rich condition
- High fuel pressure or faulty fuel pressure regulator
- Contaminated sensor from oil or coolant burning
Typical repair cost
$150 – $500
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0153 code?
For short trips, usually yes, but you shouldn't lean on it. Because this upstream sensor helps control fuel, a lasting rich condition can foul plugs and stress the catalytic converter, so get it checked soon.
How much does it cost to fix a P0153 code?
Most repairs run $150 to $500. A simple oxygen sensor replacement is at the low end, while diagnosing and fixing a fuel injector or pressure problem can raise the total.
Is a P0153 code serious?
It's a moderate-severity code. It usually won't strand you, but a prolonged rich condition wastes fuel and can damage the catalytic converter over time, so it's worth addressing promptly.
Why would high voltage mean a rich condition?
An oxygen sensor produces higher voltage when it senses little oxygen in the exhaust, which happens when the mixture is rich with fuel. A steadily high reading therefore often points to too much fuel, though a faulty sensor or wiring short can mimic it.