### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Exhaust leaks [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 System Too Lean
– Potential Issues:
Fuel delivery problems
– Troubleshooting Process:
Smoke test intake [1][7]
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## Auto Repair Terminology
### Skid Prevention Technology
– Function: Prevents wheel lockup [7]
### Vehicle Computer System
– Responsibility: Manages fuel injection [7]
### Transmission System Parts
– Includes: Differential [7]
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## Repair Process Steps
1. **Symptom Assessment**:
Perform visual inspection
2. **System Verification**:
Measure resistance
3. **Component Installation**:
Use OEM parts
4. **System Validation**:
Confirm warning light reset
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## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Autel | Live data streaming |
| Physical Equipment | Torque wrench | Electrical testing |
—
## Technical Data Resources
### Mechanical Information System
– Features:
TSB access [8]
OEM specifications
### Mobile Applications
– Vehicle Service App:
ECU pinouts [5]
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## Budget Repair Strategies
– Regular maintenance avoids costly repairs
– Learn basic diagnostics to prevent mechanic overselling
– Select certified components when OEM prices prohibitive [7]