P0133moderate severityPowertrain
O2 Sensor Circuit Slow Response Bank 1 Sensor 1
on 2021 Mazda MX-5 Miata 2.0L I4 · RWD
What this code means
The upstream O2 sensor on Bank 1 is responding too slowly to fuel mixture changes.
Symptoms
- Check Engine Light
- Poor fuel economy
- Failed emissions test
- Slight hesitation
Common causes
- Aging O2 sensor
- Contaminated sensor (oil/coolant/fuel additives)
- Exhaust leak
- Wiring issue
Diagnostic steps
- Monitor O2 sensor switching frequency (should be >6 switches in 10 sec)
- Check for exhaust leaks
- Inspect sensor for contamination
- Test response to induced rich/lean
Repair notes
Replace O2 sensor. This is a common wear item.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1