### P0420 Catalyst System Efficiency Below Threshold
– Common Causes:
Exhaust leaks [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Potential Issues:
Fuel delivery problems
– Troubleshooting Process:
Smoke test intake [1][7]
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## Car Maintenance Terms
### Electronic Braking System
– Purpose: Enables safe braking [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Monitors sensors [7]
### Drivetrain Components
– Contains: Drive axles [7]
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## Mechanical Fixing Workflow
1. **Symptom Assessment**:
Conduct road test
2. **System Verification**:
Test continuity
3. **Component Installation**:
Clear error codes
4. **System Validation**:
Ensure proper operation
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## Critical Instruments
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Code Reader | Innova | Live data streaming |
| Physical Equipment | Multimeter | Electrical testing |
—
## Repair Documentation Sources
### Auto Repair Source
– Features:
Component locations [8]
OEM specifications
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
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## Cost-Saving Tips
– Preventative service extends vehicle life
– Learn basic diagnostics to prevent mechanic overselling
– Select certified components when OEM prices prohibitive [7]