P0157 Fault Diagnosis and Fix in 2004 Jeep Liberty - O2 Sensor Wiring Short to Ground
I've been experiencing an intermittent check engine light with code P0157, which indicates 'Bank 2 Sensor 2 shorted to ground'. Initially, the code would appear and then disappear on its own. Eventually, it persisted and wouldn't clear, prompting me to inspect under the vehicle. Upon inspection, I found that the oxygen sensor located after the catalytic converter had damaged wiring due to rubbing against the body mount. The insulation had worn away completely, causing a direct short to ground. After carefully separating the wires and applying electrical tape for insulation, the issue was resolved. The P0157 code cleared immediately and has not returned since. This repair confirms that physical damage from wire abrasion is the root cause in this case.
The issue was specifically with the wiring after the O2 sensor connector, which is a common point of friction on this model. If the problem lies in the wires after the connector, I'd recommend replacing the oxygen sensor with a new OEM dealer part—electrical tape alone won't provide long-term protection and may fail again under vibration or heat. Well done identifying the root cause!