### P0420 Catalytic Converter Issue
– Frequent Reasons:
Faulty oxygen sensor [1]
– Suggested Repairs:
Diagnose fuel trim https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Likely Problems:
Vacuum leaks
– Diagnostic Steps:
Inspect injectors [1][7]
—
## Car Maintenance Terms
### Skid Prevention Technology
– Function: Enables safe braking [7]
### Engine Management Unit
– Role: Controls ignition timing [7]
### Powertrain Elements
– Includes: Drive axles [7]
—
## Repair Process Steps
1. **Symptom Assessment**:
Conduct road test
2. **Part Evaluation**:
Test continuity
3. **Defective Unit Swap**:
Clear error codes
4. **System Validation**:
Ensure proper operation
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Innova | Live data streaming |
| Hand Instruments | Torque wrench | Component repair |
—
## Repair Documentation Sources
### Vehicle Service Database
– Features:
TSB access [8]
Factory repair procedures
### Digital Assistants
– Vehicle Service App:
ECU pinouts [5]
—
## Budget Repair Strategies
– Preventative service avoids costly repairs
– Learn basic diagnostics to prevent mechanic overselling
– Use aftermarket parts when OEM prices prohibitive [7]
