DTC P0171: 1/1 O2 Sensor Fuel System Lean Or DTC P0174: 2/1 O2 Sensor Fuel System Lean: Notes

NOTE: 1/1 HO2S may also be referred to as an upstream oxygen sensor. On Federal 3.9L, 5.2L (gasoline) and 5.9L models, 1/1 HO2S is located in front of catalytic converter. On Calif. 3.9L, 5.2L (gasoline) and 5.9L models, 1/1 HO2S is located just above left side mini-catalytic converter. On all 5.2L CNG models, 1/1 HO2S is located in front of catalytic converter.

NOTE: 1/2 HO2S may also be referred to as a downstream oxygen sensor. On Federal 3.9L, 5.2L (gasoline) and 5.9L models, 1/2 HO2S is located behind catalytic converter. On Calif. 3.9L, 5.2L (gasoline) and 5.9L models, 1/2 HO2S is located just below left side mini-catalytic converter. On all 5.2L CNG models, there is no 1/2 HO2S.

NOTE: 2/1 HO2S may also be referred to as an upstream oxygen sensor. 2/1 HO2S is located just above right side mini-catalytic converter.

NOTE: 2/2 HO2S may also be referred to as a downstream oxygen sensor. 2/2 HO2S is located just below right side mini-catalytic converter.

NOTE: DTCs listed above are diagnosed using the same test. For component location, see COMPONENT LOCATIONS . For connector identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see WIRING DIAGRAMS article. If Powertrain Control Module (PCM) is replaced, PCM must be reprogrammed. See PROGRAMMING . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-5 under VERIFICATION TESTS to ensure system is functioning properly.