### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Worn catalytic converter [1]
– Recommended Fixes:
Diagnose fuel trim https://carautorepair.site/
### P0171 Fuel Mixture Imbalance
– Likely Problems:
Faulty MAF sensor
– Troubleshooting Process:
Check fuel pressure [1][7]
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## Vehicle Service Vocabulary
### Skid Prevention Technology
– Function: Prevents wheel lockup [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Controls ignition timing [7]
### Drivetrain Components
– Contains: Drive axles [7]
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## Service Procedure Stages
1. **Symptom Assessment**:
Conduct road test
2. **Part Evaluation**:
Test continuity
3. **Parts Replacement**:
Use OEM parts
4. **System Validation**:
Test drive vehicle
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## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Innova | Retrieve DTCs |
| Mechanical Tools | Torque wrench | Electrical testing |
—
## Technical Data Resources
### Vehicle Service Database
– Capabilities:
Wiring diagrams [8]
Technical illustrations
### Mobile Applications
– Auto Repair Documents:
ECU pinouts [5]
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## Cost-Saving Tips
– Preventative service extends vehicle life
– Learn basic diagnostics to prevent mechanic overselling
– Select certified components when budget constrained [7]
