P0131 on Your 2022 Acura TLX
Code P0131 on your 2022 Acura TLX indicates the Bank 1 Sensor 1 air-fuel ratio sensor is reading below its expected voltage range. The second-generation TLX offers a 2.0L turbocharged four-cylinder (K20C6, 272 hp) on standard models and a 3.0L twin-turbo V6 (KA-J30AB, 355 hp) on the Type S. On the four-cylinder, there's one bank. On the Type S V6, Bank 1 is the rear bank of the transverse engine. Both use Denso wideband A/F sensors in the upstream position.
Symptoms
- Check engine light illuminated
- Reduced fuel economy
- Subtle idle roughness — noticeable on a sedan designed for refinement
- Minor hesitation during acceleration
- Slightly reduced throttle response on the Type S
Causes on the 2022 TLX
1. A/F Sensor Degradation
Both TLX engines are turbocharged, meaning the upstream A/F sensor operates in a high-heat environment downstream of the turbo(s). The Denso wideband sensor's pumping cell degrades faster in these conditions compared to naturally aspirated applications. On the Type S twin-turbo V6, the heat is even more intense. Sensor contamination from engine oil vapors through the PCV system is also possible.
2. Wiring or Connector Issues
The TLX's engine bay is tightly packaged, especially on the Type S with its larger twin-turbo V6. The A/F sensor harness routes near exhaust components and turbo heat shields, where insulation can degrade. Connector corrosion from moisture exposure is also possible.
3. Exhaust Leak
The turbo-to-downpipe connection on the 2.0T, or the twin-turbo exhaust connections on the Type S, can develop leaks from gasket degradation or loose bolts. Fresh air entering the exhaust past the A/F sensor creates a false lean reading.
4. Lean Running Condition
Boost system leaks, vacuum leaks, or MAF sensor contamination can cause genuine lean operation. P0171 alongside P0131 confirms a real lean condition rather than a sensor fault.
Diagnostic Steps
- Scan all codes and check for P0171 companion code.
- Monitor A/F sensor pump current — should respond smoothly to throttle changes.
- On the Type S, compare Bank 1 and Bank 2 sensor data.
- Inspect the sensor connector for heat damage or corrosion.
- Check turbo exhaust connections for leaks.
- Review fuel trims for lean indications.
Repair Costs
Genuine Denso A/F sensor: $120–$300. Acura dealer labor: $100–$220. Total: $220–$520. The Type S V6 may have higher sensor costs due to the specific application. The 2022 TLX is under the 4-year/50,000-mile basic warranty and 8-year/80,000-mile emissions warranty.
Priority
Fix within two weeks. The TLX's turbocharged engines depend on precise A/F sensor feedback. Under warranty, it's a free repair — schedule a dealer appointment promptly.