P0144 indicates the downstream oxygen sensor on engine bank 1 is reporting a consistently high voltage signal to the powertrain control module. This suggests the sensor detects a rich exhaust condition or the sensor circuit is shorted to power. It specifically monitors the catalytic converter's output on the first bank of cylinders.
Internal sensor failure often causes the signal to stick at a high voltage level.
The sensor signal wire may be shorted to a voltage source in the harness.
Oil or coolant entering the exhaust can foul the sensor element.
Leaking injectors or high fuel pressure can cause genuinely rich exhaust gas.
Leaks upstream of the sensor can introduce false oxygen readings.
Internal controller damage is possible but statistically very rare.
Yes, but prolonged driving with a rich condition can damage the catalytic converter.
No, PCM failure is extremely rare; replace the sensor and check wiring first.
It may clear if the condition was temporary, but it will likely return if the fault persists.
Not directly, this code points to the sensor circuit, though catalyst efficiency codes are related.