Component Inspection

Engine

Engine Control - P2098 Post Catalyst Fuel Trim System B2 Too Lean - Component Inspection

Component Inspection

1. 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
1) Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure
NO
1) Go to next step as below
2. 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?
YES
1) Replace TWC and go to "Verification of Vehicle Repair" procedure
NO
1) Go to next step as below
3. 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 ECM)
- 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 Scantool and monitor the "O2 SNSR VOL.-B2/S1" and "O2 SNSR VOL.-B2/S2" parameters on the Scantool data list.
A. Specification : - Front HO2S (O2 SNSR VOL.-B2/S1) : Approx. 0 - 1 V with idle after warm up Sensor voltage increase during engine acceleration and decrease during engine deceleration
Approx. 0 V ~ 0.4 V when fuel cut
- Rear HO2S (O2 SNSR VOL.-B2/S2) : Above 0.4 V at idle
(4) Was a problem found in any of the above areas?
YES
1) Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure
NO
1) Check for poor connection between ECM 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