P1148
Closed Loop Control Function Bank 1
Severity
⚠️ MediumCan you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)
Symptoms
- Increased fuel consumption
- Unstable engine operation at idle
- Reduced engine power
- Check engine light comes on
- Dips during acceleration
Causes
- Bank 1 oxygen sensor malfunction
- Air leaks in the intake manifold
- Problems with fuel injectors
- Malfunction of the mass air flow sensor (MAF)
- Damage to wiring or sensor connectors
How to Fix
- Check the condition of the bank 1 oxygen sensor
- Examine the system for air leaks
- Check the operation of the fuel injectors
- Test the mass air flow sensor and its circuit
- Inspect the wiring harness and sensor connectors