P2243

O2 Sensor Reference Voltage Circuit/Open Bank 1 Sensor 1

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–67 (est.)

Symptoms

Check Engine light comes on
Increased fuel consumption
Unstable engine idling
Reduced engine power
Black smoke from the exhaust pipe

Causes

Open or short circuit in the oxygen sensor power supply circuit
Malfunction of the O2 sensor itself (bank 1, sensor 1)
Poor contact in the sensor connector
Damage to the wiring harness near the sensor
Engine ECU malfunction

How to Fix

Check the integrity of the sensor power supply circuit
Inspect the sensor connector for damage and oxidation.
Check the resistance and signal of the oxygen sensor
If necessary, replace the oxygen sensor (bank 1, sensor 1)
Check the performance of the engine ECU

Related codes

P0137 P0138 P0140