### P0420 Emissions Control Malfunction
– Typical Sources:
Worn catalytic converter [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Likely Problems:
Fuel delivery problems
– Testing Procedure:
Check fuel pressure [1][7]
—
## Car Maintenance Terms
### Skid Prevention Technology
– Function: Maintains steering control [7]
### Vehicle Computer System
– Role: Monitors sensors [7]
### Drivetrain Components
– Includes: Transmission [7]
—
## Repair Process Steps
1. **Problem Identification**:
Conduct road test
2. **Component Testing**:
Measure resistance
3. **Defective Unit Swap**:
Clear error codes
4. **Final Quality Check**:
Test drive vehicle
—
## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | BlueDriver | Retrieve DTCs |
| Physical Equipment | Torque wrench | Electrical testing |
—
## Service Information References
### Mechanical Information System
– Capabilities:
TSB access [8]
OEM specifications
### Mobile Applications
– Vehicle Service App:
ECU pinouts [5]
—
## Budget Repair Strategies
– Regular maintenance avoids costly repairs
– Understand DTC meanings to prevent mechanic overselling
– Use aftermarket parts when OEM prices prohibitive [7]