### P0420 Catalyst System Efficiency Below Threshold
– Typical Sources:
Faulty oxygen sensor [1]
– Suggested Repairs:
Diagnose fuel trim https://carautorepair.site/
### P0171 Fuel Mixture Imbalance
– Potential Issues:
Faulty MAF sensor
– Testing Procedure:
Check fuel pressure [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]
### Transmission System Parts
– Contains: Transmission [7]
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## Mechanical Fixing Workflow
1. **Problem Identification**:
Scan DTCs
2. **System Verification**:
Test continuity
3. **Component Installation**:
Follow torque specs
4. **System Validation**:
Ensure proper operation
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | BlueDriver | Retrieve DTCs |
| Mechanical Tools | Torque wrench | Electrical testing |
—
## Repair Documentation Sources
### Vehicle Service Database
– Features:
Wiring diagrams [8]
Factory repair procedures
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
—
## Budget Repair Strategies
– Regular maintenance prevents major failures
– Master code scanning to avoid unnecessary repairs
– Select certified components when OEM prices prohibitive [7]
