### P0420 Catalyst System Efficiency Below Threshold
– Common Causes:
Exhaust leaks [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Possible Defects:
Vacuum leaks
– Troubleshooting Process:
Check fuel pressure [1][7]
—
## Car Maintenance Terms
### Electronic Braking System
– Purpose: Maintains steering control [7]
### Vehicle Computer System
– Role: Monitors sensors [7]
### Drivetrain Components
– Contains: Transmission [7]
—
## Service Procedure Stages
1. **Problem Identification**:
Perform visual inspection
2. **Part Evaluation**:
Check voltage
3. **Defective Unit Swap**:
Follow torque specs
4. **Post-Repair Verification**:
Confirm warning light reset
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## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | Innova | Live data streaming |
| Hand Instruments | Smoke machine | Electrical testing |
—
## Repair Documentation Sources
### Mechanical Information System
– Features:
Wiring diagrams [8]
Factory repair procedures
### Digital Assistants
– Vehicle Service App:
Electrical diagrams [5]
—
## Affordable Maintenance Advice
– Preventative service extends vehicle life
– Learn basic diagnostics to prevent mechanic overselling
– Select certified components when budget constrained [7]
