### P0420 Catalyst System Efficiency Below Threshold
– Common Causes:
Worn catalytic converter [1]
– Suggested Repairs:
Replace catalytic converter https://carautorepair.site/
### P0171 Air-Fuel Ratio Error
– Potential Issues:
Vacuum leaks
– Diagnostic Steps:
Smoke test intake [1][7]
—
## Car Maintenance Terms
### ABS (Anti-Lock Brake System)
– Purpose: Enables safe braking [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Controls ignition timing [7]
### Transmission System Parts
– Includes: Differential [7]
—
## Repair Process Steps
1. **Symptom Assessment**:
Scan DTCs
2. **Part Evaluation**:
Test continuity
3. **Component Installation**:
Clear error codes
4. **Final Quality Check**:
Ensure proper operation
—
## Necessary Equipment
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | Innova | Retrieve DTCs |
| Mechanical Tools | Torque wrench | Electrical testing |
—
## Repair Documentation Sources
### Auto Repair Source
– Capabilities:
Component locations [8]
OEM specifications
### Mobile Applications
– Auto Repair Documents:
ECU pinouts [5]
—
## Cost-Saving Tips
– Routine checkups avoids costly repairs
– Learn basic diagnostics to prevent mechanic overselling
– Use aftermarket parts when OEM prices prohibitive [7]
