### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Faulty oxygen sensor [1]
– Suggested Repairs:
Diagnose fuel trim https://carautorepair.site/
### P0171 Fuel Mixture Imbalance
– Possible Defects:
Faulty MAF sensor
– Diagnostic Steps:
Inspect injectors [1][7]
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## Auto Repair Terminology
### Electronic Braking System
– Purpose: Enables safe braking [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Controls ignition timing [7]
### Powertrain Elements
– Contains: Drive axles [7]
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## Repair Process Steps
1. **Initial Diagnosis**:
Perform visual inspection
2. **System Verification**:
Check voltage
3. **Defective Unit Swap**:
Use OEM parts
4. **System Validation**:
Test drive vehicle
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## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | BlueDriver | Live data streaming |
| Mechanical Tools | Smoke machine | Component repair |
—
## Repair Documentation Sources
### Mechanical Information System
– Features:
Wiring diagrams [8]
OEM specifications
### Digital Assistants
– Auto Repair Documents:
ECU pinouts [5]
—
## Affordable Maintenance Advice
– Regular maintenance prevents major failures
– Master code scanning to avoid unnecessary repairs
– Use aftermarket parts when OEM prices prohibitive [7]
