### P0420 Emissions Control Malfunction
– Frequent Reasons:
Worn catalytic converter [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 System Too Lean
– Possible Defects:
Fuel delivery problems
– Troubleshooting Process:
Smoke test intake [1][7]
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## Car Maintenance Terms
### ABS (Anti-Lock Brake System)
– Purpose: Enables safe braking [7]
### Engine Management Unit
– Role: Monitors sensors [7]
### Drivetrain Components
– Includes: Drive axles [7]
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## Service Procedure Stages
1. **Initial Diagnosis**:
Conduct road test
2. **System Verification**:
Test continuity
3. **Defective Unit Swap**:
Clear error codes
4. **Final Quality Check**:
Test drive vehicle
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## Critical Instruments
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Autel | Retrieve DTCs |
| Hand Instruments | Torque wrench | Component repair |
—
## Service Information References
### Mechanical Information System
– Capabilities:
TSB access [8]
Technical illustrations
### Digital Assistants
– Vehicle Service App:
Component testing guides [5]
—
## Cost-Saving Tips
– Preventative service prevents major failures
– Understand DTC meanings to prevent mechanic overselling
– Install quality alternatives when OEM prices prohibitive [7]
