P1134moderate severityPowertrain
HO2S Bank 1 Sensor 1 Slow Response
on 2016 Hyundai Equus 5.0L V8 · FWD
What this code means
The PCM has detected that the upstream heated oxygen sensor on Bank 1 is switching between rich and lean too slowly. The sensor response time exceeds the maximum allowable threshold for accurate fuel control.
Symptoms
- Check Engine Light
- Poor fuel economy
- Failed emissions test
- Slightly rough idle
Common causes
- Aging O2 sensor with degraded response time
- O2 sensor contaminated with silicone or coolant
- Exhaust leak near sensor
- O2 sensor heater circuit issue
- Wiring causing signal delay
Diagnostic steps
- Monitor O2 sensor switching rate on scan tool at steady 2500 RPM
- Compare response time to specification
- Check O2 sensor heater circuit operation
- Inspect for exhaust leaks near sensor
- Check sensor wiring for high resistance
Repair notes
Replace the upstream O2 sensor on Bank 1 if the response time exceeds specification.
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