### P0420 Catalyst System Efficiency Below Threshold
– Typical Sources:
Exhaust leaks [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Potential Issues:
Fuel delivery problems
– Testing Procedure:
Inspect injectors [1][7]
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## Auto Repair Terminology
### ABS (Anti-Lock Brake System)
– Function: Maintains steering control [7]
### Engine Management Unit
– Role: Monitors sensors [7]
### Drivetrain Components
– Contains: Drive axles [7]
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## Repair Process Steps
1. **Initial Diagnosis**:
Conduct road test
2. **Part Evaluation**:
Check voltage
3. **Defective Unit Swap**:
Follow torque specs
4. **Post-Repair Verification**:
Test drive vehicle
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | Innova | Live data streaming |
| Physical Equipment | Torque wrench | Component repair |
—
## Service Information References
### Mechanical Information System
– Features:
Wiring diagrams [8]
Factory repair procedures
### Mobile Applications
– Vehicle Service App:
Electrical diagrams [5]
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## Budget Repair Strategies
– Routine checkups prevents major failures
– Understand DTC meanings to avoid unnecessary repairs
– Install quality alternatives when budget constrained [7]
