P2248 — O2 Sensor Reference Voltage Performance Bank 2 Sensor 1
P2248 — O2 Sensor Reference Voltage Performance Bank 2 Sensor 1. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: aged or contaminated oxygen sensor, exhaust leak near the sensor, damaged sensor wiring or connector.
powertrain (engine/transmission)
Is it safe to drive?
Short-term driving is OK You can usually drive for a while: the engine runs on a default fuel strategy, which costs you fuel and emissions. Fix it soon — prolonged driving with a bad O2 sensor can overheat and damage the catalytic converter.
How to diagnose with an OBD scanner
- Read the code and freeze frame Connect an OBD2 scanner, confirm P2248 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
- Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
- Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the oxygen sensor circuit for damage, corrosion, chafing or poor contact.
- Subsystem check Watch the sensor voltage in live data: a healthy upstream sensor switches rapidly between roughly 0.1 and 0.9 V.
- Subsystem check Measure heater resistance on the sensor connector and check the heater fuse and relay.
- Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2248 does not return.
Approximate repair cost
Repair cost depends on which component actually failed. Typical scenarios for P2248 (parts and labor, USD, independent shop rates): Replace the oxygen sensor: $150–$450; Fix an exhaust leak near the sensor: $100–$300; Repair sensor wiring: $80–$250. Overall, fixing P2248 usually costs between $80 and $450. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.
Common questions
What does OBD2 code P2248 mean?
P2248 — O2 Sensor Reference Voltage Performance Bank 2 Sensor 1. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: aged or contaminated oxygen sensor, exhaust leak near the sensor, damaged sensor wiring or connector.
How do I diagnose P2248 myself?
Start with a scan: confirm P2248, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the oxygen sensor circuit, and verify the suspect component against live data before buying parts.
What are the symptoms of P2248?
Drivers most often notice: Check Engine Light on, sluggish throttle response, rough idle, failed emissions test.
How much does it cost to fix P2248?
Replace the oxygen sensor — $150–$450; Fix an exhaust leak near the sensor — $100–$300; Repair sensor wiring — $80–$250. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.
What is the most common cause of P2248?
The most common causes are: aged or contaminated oxygen sensor, exhaust leak near the sensor, damaged sensor wiring or connector.
What does P2248 mean?
P2248 is logged by the onboard diagnostics when the oxygen sensor circuit does not behave as expected. The official definition is “O2 Sensor Reference Voltage Performance Bank 2 Sensor 1”. This is a powertrain (engine/transmission) category code.
In this definition, “Bank 2” is the side of the engine opposite to cylinder 1 and “Sensor 1” is the upstream (before the catalytic converter) sensor. Mixing up banks and sensor positions is the most common DIY mistake with this code — verify the physical location before replacing anything.
To set P2248, the control module compares live readings of the oxygen sensor circuit against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.
Common symptoms of P2248
- Check Engine Light on
- sluggish throttle response
- rough idle
- failed emissions test
- increased fuel consumption
What causes P2248?
- damaged sensor wiring or connector
- ECM signal circuit fault
- oil or coolant contamination of the sensor tip
- blown sensor heater fuse
How to diagnose P2248
- Connect an OBD2 scanner, confirm P2248 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
- Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
- Visually inspect the wiring harness and connectors related to the oxygen sensor circuit for damage, corrosion, chafing or poor contact.
- Watch the sensor voltage in live data: a healthy upstream sensor switches rapidly between roughly 0.1 and 0.9 V.
- Measure heater resistance on the sensor connector and check the heater fuse and relay.
- Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2248 does not return.
How to fix P2248
Start with the cheapest and most common causes before replacing expensive parts:
- Replace the oxygen sensor — $150–$450
- Fix an exhaust leak near the sensor — $100–$300
- Repair sensor wiring — $80–$250
How much does it cost to fix P2248?
Repair cost depends on which component actually failed. Typical scenarios for P2248 (parts and labor, USD, independent shop rates):
- Replace the oxygen sensor: $150–$450
- Fix an exhaust leak near the sensor: $100–$300
- Repair sensor wiring: $80–$250
Overall, fixing P2248 usually costs between $80 and $450. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.
Can you drive with P2248?
You can usually drive for a while: the engine runs on a default fuel strategy, which costs you fuel and emissions. Fix it soon — prolonged driving with a bad O2 sensor can overheat and damage the catalytic converter.