### P0420 Emissions Control Malfunction
– Frequent Reasons:
Exhaust leaks [1]
– Suggested Repairs:
Repair exhaust system https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Potential Issues:
Vacuum leaks
– Diagnostic Steps:
Check fuel pressure [1][7]
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## Auto Repair Terminology
### ABS (Anti-Lock Brake System)
– Function: Enables safe braking [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Monitors sensors [7]
### Transmission System Parts
– Contains: Transmission [7]
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## Mechanical Fixing Workflow
1. **Initial Diagnosis**:
Perform visual inspection
2. **Part Evaluation**:
Measure resistance
3. **Parts Replacement**:
Clear error codes
4. **Post-Repair Verification**:
Confirm warning light reset
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## Critical Instruments
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Autel | Retrieve DTCs |
| Hand Instruments | Multimeter | Electrical testing |
—
## Repair Documentation Sources
### Vehicle Service Database
– Features:
Wiring diagrams [8]
Technical illustrations
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
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## Cost-Saving Tips
– Routine checkups extends vehicle life
– Learn basic diagnostics to avoid unnecessary repairs
– Select certified components when OEM prices prohibitive [7]