Test TC-192A - 1/1 O2 Sensor Slow During Catalyst Monitor

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION DIRECTORY. For component location see wiring diagram in the WIRING DIAGRAMS article.

CAUTION: Allow Heated Oxygen Sensor (HO2S) to cool to room temperature before checking resistance.

NOTE: 1/1 HO2S is located in upstream position. On models with 2 upstream HO2S, 1/1 HO2S is located in left upstream position.

1/1 O2 SENSOR SLOW DURING CATALYST MONITOR DTC sets if1/1 Heated Oxygen Sensor (HO2S) voltage is switches from less than 0.39 volt to more than 0.60 volt fewer times than required. Possible causes are: exhaust leak, fuel contamination, HO2S heater failure, defective O2S, defective wiring or connectors, or engine mechanical problems. Go to next step.
Start engine. Check exhaust system for leaks between engine and catalytic converter. Repair exhaust system as necessary and perform TEST VER-5A. If exhaust system is okay, go to next step.
Check exhaust for excessive smoke caused by oil or coolant consumption. Repair engine mechanical condition as necessary, replace catalytic converter and HO2Ss, and perform TEST VER-5A. If engine mechanical condition is okay, go to next step.
Turn ignition off. Disconnect 1/1 HO2S connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-5A. If connector and terminals are okay, go to next step.
Using an external ohmmeter, check resistance between ground and 1/1 HO2S connector, ground circuit (Black/Light Blue wire). If resistance is 5 ohms or more, repair open sensor ground circuit and perform TEST VER-5A. If resistance is less than 5 ohms, go to next step.
Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-5A. If connectors and terminals are okay, replace 1/1 HO2S and perform TEST VER-5A.