Component Inspection

■ Check Exhaust system 

1. Visually/physically inspect the following conditions:
   • Exhaust system between HO2S and Three way catalyst for air leakage, restriction and damage.
   • Damage, and for loose or missing hardware.
2. Was a problem found in any of the above areas?

   YES 

   • Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Go to next step below.

■ Check TWC 

1. Visually/physically inspect the three-way catalyst (TWC) converter for the following damage:
   • Severe discoloration caused by excessive temperature.
   • Dents and holes.
   • Internal rattle caused by a damaged catalyst.
2. Also, ensure that the TWC is a proper original equipment manufacturer part.
3. Was a problem found in any of the above areas?

   YES 

   • Replace TWC and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Go to next step below.

■ Check HO2S 

1. Visually/physically inspect the HO2S for the following conditions:
   • Ensure that the HO2S is securely installed. (Pigtail and wiring harness not making contact with the exhaust pipe)
   • Check for corrosion on terminals and terminal tension (at the HO2S and at the PCM)
   • Front HO2S for silicon contamination. This contamination will be indicated by a white powdery coating on the portion of the sensor exposed to the exhaust stream and this will result in a but false (high) voltage signal.
   • Fuel, engine coolant or oil contamination.
   • Use of improper sealant.
   • If contamination is evident on the HO2S, Fix the source of the sensor contamination before replacing the sensor to prevent future contamination. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
2. Warm up the engine to normal operating temperature and let it idle.
3. Connect GDS and monitor the "O2 SNSR VOL.-B1/S1" and "O2 SNSR VOL.-B1/S2" parameters on the GDS data list.

   Specification: 

   • Front HO2S (O2 SNSR VOL.-B1/S1): Approx. 0~1V with idle after warm up Sensor voltage increase during engine acceleration and decrease during engine deceleration.

     Approx. 0V ~ 0.4 V when fuel cut

   • Rear HO2S (O2 SNSR VOL.-B1/S2): Above 0.4V at idle
4. Was a problem found in any of the above areas?

   YES 

   • Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.