The P1401 code in your 2022 Lexus RC indicates insufficient flow in the Exhaust Gas Recirculation system. This Toyota/Lexus-specific code signals the EGR valve isn't flowing enough exhaust gas for emissions control.
EGR in Performance Vehicles
Even performance vehicles like the RC use EGR for emissions compliance. The system recirculates exhaust to lower combustion temperatures and reduce NOx. P1401 indicates the flow is below required levels.
Common Causes of P1401
- Carbon-clogged EGR valve
- Blocked EGR passages
- EGR valve failure
- Vacuum leak (if vacuum operated)
- EGR position sensor failure
- ECU control issues
Symptoms of EGR Flow Issues
- Check engine light on
- Failed emissions test
- Possible engine knock
- Slightly higher operating temperature
- Often no noticeable drivability issues
- Increased NOx emissions
RC Emissions Compliance
The RC must meet emissions standards while delivering performance. EGR issues can cause emissions test failures even if the car drives normally.