<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a problem with the O2 sensor reference voltage performance in Bank 2 Sensor 1. This could be due to a faulty O2 sensor, wiring issues, or a malfunctioning Engine Control Module (ECM).</li> <li><b>Poor Fuel Economy</b>: A malfunctioning O2 sensor can cause incorrect air-fuel mixture readings, leading to inefficient fuel consumption. Potential causes include a defective O2 sensor or issues with the sensor's wiring.</li> <li><b>Rough Idle</b>: An incorrect O2 sensor reading can result in an unstable idle due to improper air-fuel mixture adjustments. This may be caused by a failing O2 sensor or a problem with the ECM.</li> <li><b>Increased Emissions</b>: Faulty O2 sensor readings can lead to higher emissions as the engine may run too rich or too lean. This is often due to a defective O2 sensor or related wiring issues.</li> </ul>

<ul><li>The front oxygen sensor on Bank 2 may be faulty, leading to incorrect voltage readings.</li><li>An open or shorted harness in the front oxygen sensor on Bank 2 can disrupt the sensor's performance.</li><li>Poor electrical connections in the front oxygen sensor circuit on Bank 2 can cause intermittent or incorrect signals.</li></ul>

<ul> <li><b>Retrieve Codes and Freeze Frame Data</b>: Connect the diagnostic scanner to the vehicle's diagnostic port. Retrieve all stored codes and pertinent freeze frame data. Write down this information for reference.</li> <li><b>Clear Codes and Test Drive</b>: Clear the codes and test drive the vehicle until the code is restored or the PCM enters readiness mode. If the code is restored, proceed with the diagnosis.</li> <li><b>Perform Visual Inspection</b>: Inspect related wiring and connectors for damage. Repair or replace any cut, burned, or damaged wiring.</li> <li><b>Test O2 Sensor Voltage</b>: Use a DVOM to test the O2 sensor voltage at the appropriate connector pin near the sensor. If no voltage is detected, check system fuses and replace any blown fuses.</li> <li><b>Check PCM Connector Voltage</b>: Test the corresponding circuit at the PCM connector. If no voltage is detected, suspect an open circuit between the sensor and the PCM. If voltage is detected, suspect a defective PCM or PCM programming error.</li> <li><b>Test O2 Sensor Functionality</b>: Start the engine and allow it to reach normal operating temperature. Observe oxygen sensor input data on the scanner. Pre-cat sensors should cycle between 1 and 900 millivolts. Post-cat sensors should also cycle but remain relatively stable. Replace any sensors that fail to cycle adequately.</li> <li><b>Check for Technical Service Bulletins (TSB)</b>: Search for any TSBs that match the code, vehicle year, make, model, and symptoms. A relevant TSB may provide a quick solution.</li></ul>

<p>The DTC code P2248 indicates an issue with the O2 Sensor Reference Voltage Performance for Bank 2 Sensor 1. This can affect the air-fuel ratio, leading to poor engine performance and increased emissions.</p><ul><li><b>Immediate Actions:</b> Inspect the O2 sensor and its wiring for damage or corrosion.</li><li>Check the reference voltage from the ECU.</li><li>Replace the O2 sensor if necessary.</li></ul><p>Delaying repair can result in reduced fuel efficiency and potential damage to the catalytic converter.</p>