### P0420 Catalyst System Efficiency Below Threshold
– Common Causes:
Worn catalytic converter [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 System Too Lean
– Likely Problems:
Fuel delivery problems
– Diagnostic Steps:
Inspect injectors [1][7]
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## Car Maintenance Terms
### Electronic Braking System
– Purpose: Enables safe braking [7]
### Vehicle Computer System
– Responsibility: Monitors sensors [7]
### Transmission System Parts
– Includes: Transmission [7]
—
## Service Procedure Stages
1. **Symptom Assessment**:
Scan DTCs
2. **Part Evaluation**:
Measure resistance
3. **Component Installation**:
Clear error codes
4. **Final Quality Check**:
Confirm warning light reset
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Code Reader | BlueDriver | Live data streaming |
| Mechanical Tools | Multimeter | Component repair |
—
## Repair Documentation Sources
### Vehicle Service Database
– Features:
Wiring diagrams [8]
Factory repair procedures
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
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## Cost-Saving Tips
– Regular maintenance extends vehicle life
– Learn basic diagnostics to avoid unnecessary repairs
– Use aftermarket parts when OEM prices prohibitive [7]