### P0420 Emissions Control Malfunction
– Frequent Reasons:
Faulty oxygen sensor [1]
– Recommended Fixes:
Replace catalytic converter https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Likely Problems:
Fuel delivery problems
– Troubleshooting Process:
Check fuel pressure [1][7]
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## Car Maintenance Terms
### ABS (Anti-Lock Brake System)
– Function: Maintains steering control [7]
### Engine Management Unit
– Role: Manages fuel injection [7]
### Drivetrain Components
– Contains: Transmission [7]
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## Mechanical Fixing Workflow
1. **Initial Diagnosis**:
Scan DTCs
2. **Part Evaluation**:
Check voltage
3. **Parts Replacement**:
Use OEM parts
4. **Final Quality Check**:
Ensure proper operation
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Autel | Retrieve DTCs |
| Hand Instruments | Smoke machine | Electrical testing |
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## Repair Documentation Sources
### Mechanical Information System
– Features:
Wiring diagrams [8]
OEM specifications
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
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## Cost-Saving Tips
– Routine checkups prevents major failures
– Learn basic diagnostics to avoid unnecessary repairs
– Use aftermarket parts when OEM prices prohibitive [7]