P0131 on Your 2022 Buick Envision
Code P0131 on your 2022 Buick Envision means the Bank 1 Sensor 1 oxygen sensor is reading below the ECM's expected voltage. The second-generation Envision uses a 2.0L turbocharged four-cylinder (LSY) producing 228 hp. As an inline-four, there's only one bank — Bank 1 Sensor 1 is the upstream O2 sensor positioned between the turbocharger and the catalytic converter.
Symptoms
- Check engine light on
- Reduced fuel economy below the expected 26-31 MPG combined
- Subtle idle roughness
- Mild hesitation during acceleration
- Slightly reduced turbo response
Causes on the Envision 2.0T
1. O2 Sensor Degradation
The 2.0L LSY turbo engine generates elevated exhaust temperatures at the turbo outlet, where the upstream sensor resides. Over thousands of heat cycles, the sensor's internal element degrades and loses its ability to produce accurate voltage swings. With a 2022 model potentially at 20,000–50,000 miles, sensor wear is the most common P0131 cause.
2. Wiring or Connector Issues
The Envision's engine bay routes the O2 sensor harness near the turbocharger and exhaust components. Heat damage to insulation, connector corrosion from moisture exposure, or a loosely connected plug can create signal voltage problems.
3. Exhaust Leak Near Turbo
The turbo-to-downpipe gasket on the LSY engine can develop leaks from thermal cycling. This introduces ambient air past the O2 sensor, causing a false lean reading. Check for soot marks or hissing near the turbo outlet connection.
4. Lean Condition
Boost leaks, PCV system issues, or MAF sensor contamination can cause genuine lean operation. P0171 alongside P0131 confirms a real lean condition.
Diagnostic Steps
- Scan all codes — check for P0171 companion code.
- Monitor Bank 1 Sensor 1 voltage live — should oscillate 0.1V to 0.9V at warm idle.
- Inspect the sensor connector for corrosion or heat damage near the turbo.
- Check the turbo-to-downpipe connection for exhaust leaks.
- Review fuel trims — LTFT above +15% suggests genuine lean operation.
- Replace with an OE-spec sensor if confirmed faulty.
Repair Costs
OE upstream O2 sensor: $70–$160. Shop labor: $80–$180. Total: $150–$340. Exhaust leak repairs: $100–$350. The 2022 Envision should be within the 8-year/80,000-mile federal emissions warranty. DIY replacement is moderately easy on this vehicle.
Priority
Fix within two weeks. The turbo engine needs accurate O2 feedback for proper boost and fuel management. Under warranty, it may be a free repair.