### P0420 Catalyst System Efficiency Below Threshold
– Common Causes:
Faulty oxygen sensor [1]
– Recommended Fixes:
Diagnose fuel trim https://carautorepair.site/
### P0171 Fuel Mixture Imbalance
– Potential Issues:
Faulty MAF sensor
– Diagnostic Steps:
Inspect injectors [1][7]
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## Auto Repair Terminology
### Electronic Braking System
– Function: Enables safe braking [7]
### ECM/ECU (Engine Control Module)
– Role: Monitors sensors [7]
### Drivetrain Components
– Includes: Transmission [7]
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## Repair Process Steps
1. **Initial Diagnosis**:
Perform visual inspection
2. **Part Evaluation**:
Measure resistance
3. **Parts Replacement**:
Clear error codes
4. **Final Quality Check**:
Confirm warning light reset
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Code Reader | Innova | Retrieve DTCs |
| Mechanical Tools | Torque wrench | Component repair |
—
## Service Information References
### Auto Repair Source
– Features:
Component locations [8]
Technical illustrations
### Digital Assistants
– Vehicle Service App:
Electrical diagrams [5]
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## Budget Repair Strategies
– Routine checkups avoids costly repairs
– Learn basic diagnostics to avoid unnecessary repairs
– Select certified components when OEM prices prohibitive [7]
