### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Worn catalytic converter [1]
– Recommended Fixes:
Replace catalytic converter https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Possible Defects:
Faulty MAF sensor
– Testing Procedure:
Check fuel pressure [1][7]
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## Auto Repair Terminology
### ABS (Anti-Lock Brake System)
– Function: Prevents wheel lockup [7]
### Vehicle Computer System
– Responsibility: Controls ignition timing [7]
### Powertrain Elements
– Contains: Differential [7]
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## Mechanical Fixing Workflow
1. **Symptom Assessment**:
Perform visual inspection
2. **Component Testing**:
Test continuity
3. **Defective Unit Swap**:
Follow torque specs
4. **Post-Repair Verification**:
Ensure proper operation
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | BlueDriver | Live data streaming |
| Mechanical Tools | Torque wrench | Electrical testing |
—
## Repair Documentation Sources
### Vehicle Service Database
– Capabilities:
Component locations [8]
OEM specifications
### Mobile Applications
– Auto Repair Documents:
Electrical diagrams [5]
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## Affordable Maintenance Advice
– Routine checkups prevents major failures
– Learn basic diagnostics to avoid unnecessary repairs
– Select certified components when OEM prices prohibitive [7]
