What Does P2274 Mean?
The third oxygen sensor on Bank 1 (cylinder #1 side) is reading a consistently lean fuel mixture. Sensor 3 is typically located after the catalytic converter or on vehicles with multiple catalytic converters.
Common Causes
40%
Faulty oxygen sensor (contaminated, aged, or internal failure)
30%
Exhaust leak upstream or at sensor location
20%
Damaged wiring or poor electrical connection
7%
Engine running lean on Bank 1 (vacuum leak or fuel delivery issue)
3%
Failed catalytic converter affecting sensor readings
Diagnostic Steps
1
Step 1: Visually inspect exhaust system for leaks near O2 sensor location, especially at flanges and welds
2
Step 2: Check O2 sensor wiring harness and connector for damage, chafing, or corrosion
3
Step 3: Monitor Bank 1 Sensor 3 live data and compare voltage patterns to expected behavior
4
Step 4: Review Bank 1 fuel trim values to determine if engine is actually running lean
5
Step 5: Replace O2 sensor if wiring is intact and no exhaust leaks are present
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
The third oxygen sensor on Bank 1 (cylinder #1 side) is reading a consistently lean fuel mixture. Sensor 3 is typically located after the catalytic converter or on vehicles with multiple catalytic converters.
The most common cause of P2274 (O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 3) is: Faulty oxygen sensor (contaminated, aged, or internal failure)
Typical repair costs for P2274 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but may cause increased emissions and potential catalyst damage over time. May affect fuel economy.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2274 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
