P2251

O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–89 (est.)

Symptoms

Check Engine light comes on
Increased fuel consumption
Unstable engine idling
Reduced engine power
Dips during acceleration

Causes

Broken or damaged oxygen sensor wiring
Poor contact in the sensor connector
Malfunction of the oxygen sensor itself
Problems with the engine ECU
Short circuit in control circuit

How to Fix

Check the integrity of the wiring and connectors of the sensor
Clean the contacts of the oxygen sensor connector
Check control circuit resistance
Replace the oxygen sensor if necessary
Check the performance of the engine ECU

Related codes

P0135 P0137 P0138