Faulty, worn or contaminated oxygen sensor (both sources). Broken or frayed wiring to the sensor, or faulty wiring or connections (both sources). Exhaust leak (both sources). Intake (vacuum) air leak or a faulty mass airflow sensor: OBD-Codes.com lists checking both as possible fixes, and RepairPal says they are commonly misdiagnosed as a bad oxygen sensor.

Fix any exhaust leaks (both sources). Repair shorted or frayed wiring or a bad connector (both sources). Fix an intake air leak or a faulty mass airflow sensor if testing finds one (OBD-Codes.com lists these checks; RepairPal lists them as common misdiagnoses). Replace the Bank 2 Sensor 1 oxygen sensor if it is deteriorated or contaminated (both sources).

P0153🌫 Emissions / oxygen sensorsDrive with caution, fix soon

P0153: O2 Sensor Circuit Slow Response, Bank 2 Sensor 1 (Meaning, Causes, Fixes)

Q: What does P0153 mean?

P0153 means the front (upstream) oxygen sensor on bank 2 is switching too slowly, so the engine computer isn't getting the quick rich-and-lean feedback it uses to adjust the fuel mixture on that side. A worn sensor, damaged wiring or an exhaust leak are the usual causes, and both sources say to rule out intake air leaks and the mass airflow sensor before replacing the sensor. Bank 2 Sensor 1 is the upstream oxygen sensor, in front of the catalytic converter, on the side of the engine that does not contain cylinder 1. Only V6, V8 and other engines with two cylinder banks have a bank 2. A healthy conventional oxygen sensor's voltage swings up and down quickly as the exhaust goes rich and lean, and the engine computer uses those swings to keep correcting the fuel mixture. The two sources describe the trigger a little differently. RepairPal says P0153 sets when the up-and-down "cross-counting" voltage activity from the sensor is too slow. OBD-Codes.com says the code means the air-fuel ratio is not being adjusted by the oxygen sensor signal or the engine computer as expected, or not as often as expected, once the engine is warm. RepairPal's page does not name a bank or sensor position; OBD-Codes.com identifies it as Bank 2, Sensor 1. P0153 is the bank 2 version of P0133.

Q: Can I keep driving with P0153?

Drive with caution, fix soon. Usually drivable for now, but get it checked soon. RepairPal rates P0153 Moderate: not an immediate threat to safety or the car, but it should be diagnosed within a reasonable time. OBD-Codes.com says you will likely not notice any drivability problems, and RepairPal says there are often no symptoms other than the check engine light, though emissions are often elevated. That can mean a failed emissions test.

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0153 means

Bank 2 Sensor 1 is the upstream oxygen sensor, in front of the catalytic converter, on the side of the engine that does not contain cylinder 1. Only V6, V8 and other engines with two cylinder banks have a bank 2. A healthy conventional oxygen sensor's voltage swings up and down quickly as the exhaust goes rich and lean, and the engine computer uses those swings to keep correcting the fuel mixture. The two sources describe the trigger a little differently. RepairPal says P0153 sets when the up-and-down "cross-counting" voltage activity from the sensor is too slow. OBD-Codes.com says the code means the air-fuel ratio is not being adjusted by the oxygen sensor signal or the engine computer as expected, or not as often as expected, once the engine is warm. RepairPal's page does not name a bank or sensor position; OBD-Codes.com identifies it as Bank 2, Sensor 1. P0153 is the bank 2 version of P0133.

Severity: can I keep driving?

Drive with caution, fix soon

Usually drivable for now, but get it checked soon. RepairPal rates P0153 Moderate: not an immediate threat to safety or the car, but it should be diagnosed within a reasonable time. OBD-Codes.com says you will likely not notice any drivability problems, and RepairPal says there are often no symptoms other than the check engine light, though emissions are often elevated. That can mean a failed emissions test.

Common symptoms

Check engine light on
Often no other noticeable symptoms or drivability problems (both sources)
Higher emissions in many cases (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Faulty, worn or contaminated oxygen sensor (both sources)
Broken or frayed wiring to the sensor, or faulty wiring or connections (both sources)
Exhaust leak (both sources)
Intake (vacuum) air leak or a faulty mass airflow sensor: OBD-Codes.com lists checking both as possible fixes, and RepairPal says they are commonly misdiagnosed as a bad oxygen sensor

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Read all stored codes and freeze-frame data. If P0153 shows up with lean codes such as P0171 or P0174, or with other oxygen sensor codes, look for a shared cause such as an intake leak before replacing the sensor.
Check the exhaust for leaks ahead of the bank 2 front sensor, such as a cracked manifold, a leaking gasket or a loose joint.
Find the Bank 2 Sensor 1 sensor (before the catalytic converter, on the side of the engine opposite cylinder 1) and inspect its wiring and connector for shorted or frayed wires, melted insulation or corrosion.
Check for intake air leaks, such as cracked vacuum hoses or a loose intake duct, and make sure the mass airflow sensor is working properly.
With a scan tool showing live data on a warmed-up engine, compare the bank 2 front sensor with the bank 1 front sensor. A sensor that switches noticeably slower or with a smaller swing than the other bank points to that sensor. OBD-Codes.com lists checking the sensor's switching frequency and amplitude as an advanced test.

Typical fixes

Fix any exhaust leaks (both sources)
Repair shorted or frayed wiring or a bad connector (both sources)
Fix an intake air leak or a faulty mass airflow sensor if testing finds one (OBD-Codes.com lists these checks; RepairPal lists them as common misdiagnoses)
Replace the Bank 2 Sensor 1 oxygen sensor if it is deteriorated or contaminated (both sources)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

The code comes back after a new sensor is fitted, which suggests wiring, a leak or another component
You need a smoke test for vacuum or exhaust leaks, mass airflow sensor testing, or a scope to check the sensor's switching frequency and amplitude
Several oxygen sensor or lean codes are stored at once and you need help finding the common cause

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0153?

Usually, for a short while. RepairPal rates it Moderate, and both sources say you may not notice anything other than the check engine light. Get it diagnosed soon, since emissions are often elevated.

Does P0153 always mean a bad oxygen sensor?

No. Both sources also list wiring problems and exhaust leaks, and RepairPal says the sensor is sometimes replaced when the real problem is the wiring, a vacuum leak or a faulty mass airflow sensor. Check those first.

What's the difference between P0153 and P0133?

They are the same slow-response fault on different sides of the engine. P0133 is the front oxygen sensor on bank 1 (the side with cylinder 1), and P0153 is the front oxygen sensor on bank 2.

How much does it cost to fix P0153?

Neither source gives a repair cost for P0153. It depends on whether the fix is a new sensor, a wiring repair, or fixing an exhaust or intake leak, so get it diagnosed first.

Sources

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.