Diagnostic Aids

WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

If an HO2S bank 2 sensor 1 circuit or slow response DTC or an HO2S bank 2 sensor 2 circuit or slow response DTC is set, diagnose that DTC first.

Ensure no exhaust leaks exist between the bank 2 engine head and 18 inches after the HO2S bank 2 sensor 2.

Start engine and allow ECT to reach at least 176°F (80°C). Using scan tool, monitor HO2S bank 2 sensor 2. Make sure reading is not consistently below 400 mV or consistently above 900 mV. If reading is consistently lower than 400 mV, refer to DTC P0157. See DTC P0157: HO2S CIRCUIT - LOW VOLTAGE - BANK 2 SENSOR 2 . If reading is consistently above 900 mV, refer to DTC P0158. See DTC P0158: HO2S CIRCUIT - HIGH VOLTAGE - BANK 2 SENSOR 2 . Reading should be within the 500 mV to 800 mV range. If reading is okay, the most probable cause for DTC P2098 is a weak, aging or contaminated HO2S bank 2 sensor 1.

Check for obvious contamination (oil, fuel or engine coolant) by removing sensor. Source and fix the cause of the contamination if contaminated. Replace the HO2S bank 2 sensor 1.