### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Worn catalytic converter [1]
– Recommended Fixes:
Diagnose fuel trim https://carautorepair.site/
### P0171 System Too Lean
– Potential Issues:
Faulty MAF sensor
– Troubleshooting Process:
Inspect injectors [1][7]
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## Vehicle Service Vocabulary
### ABS (Anti-Lock Brake System)
– Purpose: Maintains steering control [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Manages fuel injection [7]
### Powertrain Elements
– Includes: Differential [7]
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## Repair Process Steps
1. **Initial Diagnosis**:
Perform visual inspection
2. **Component Testing**:
Measure resistance
3. **Defective Unit Swap**:
Use OEM parts
4. **System Validation**:
Ensure proper operation
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## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Innova | Live data streaming |
| Mechanical Tools | Multimeter | Component repair |
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## Repair Documentation Sources
### Auto Repair Source
– Capabilities:
Wiring diagrams [8]
OEM specifications
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
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## Cost-Saving Tips
– Regular maintenance avoids costly repairs
– Understand DTC meanings to avoid unnecessary repairs
– Use aftermarket parts when OEM prices prohibitive [7]