### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Worn catalytic converter [1]
– Recommended Fixes:
Repair exhaust system https://carautorepair.site/
### P0171 System Too Lean
– Likely Problems:
Vacuum leaks
– Testing Procedure:
Check fuel pressure [1][7]
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## Vehicle Service Vocabulary
### ABS (Anti-Lock Brake System)
– Purpose: Prevents wheel lockup [7]
### Engine Management Unit
– Role: Monitors sensors [7]
### Transmission System Parts
– Contains: Differential [7]
—
## Mechanical Fixing Workflow
1. **Symptom Assessment**:
Perform visual inspection
2. **System Verification**:
Check voltage
3. **Defective Unit Swap**:
Use OEM parts
4. **Final Quality Check**:
Confirm warning light reset
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## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | Autel | Retrieve DTCs |
| Mechanical Tools | Multimeter | Component repair |
—
## Technical Data Resources
### Vehicle Service Database
– Features:
Wiring diagrams [8]
Technical illustrations
### Mobile Applications
– Auto Repair Documents:
ECU pinouts [5]
—
## Cost-Saving Tips
– Preventative service prevents major failures
– Understand DTC meanings to avoid unnecessary repairs
– Use aftermarket parts when budget constrained [7]
