P2196
O2 Sensor Signal Stuck Rich (Bank 1 Sensor 1)
What it means
This code means the oxygen sensor before the catalytic converter on Bank 1 is consistently reporting a rich air-fuel mixture, and the engine computer isn't seeing it switch back and forth as expected.
Is it safe to drive?
Driving with a persistent rich condition can lead to reduced fuel economy, carbon buildup, and can severely damage the catalytic converter over time. It's best to diagnose and repair this issue promptly.
Most likely causes
Faulty Front Oxygen Sensor (Bank 1 Sensor 1)
highThe oxygen sensor itself can become slow or faulty, inaccurately reporting a rich condition.
Leaking Fuel Injector(s)
mediumA leaking fuel injector will continuously add too much fuel to a cylinder, causing a rich condition.
High Fuel Pressure/Faulty Fuel Pressure Regulator
mediumExcessive fuel pressure can cause too much fuel to be delivered, leading to a rich mixture.
Contaminated or Faulty Mass Air Flow (MAF) Sensor
mediumAn inaccurate MAF reading (e.g., reporting less air than actually entering) can cause the PCM to inject too much fuel, leading to a rich condition.
Related help
Get the full diagnosis
Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.
Diagnose P2196 freeNo credit card required