### P0420 Catalyst System Efficiency Below Threshold
– Frequent Reasons:
Exhaust leaks [1]
– Suggested Repairs:
Replace catalytic converter https://carautorepair.site/
### P0171 System Too Lean
– Potential Issues:
Fuel delivery problems
– Diagnostic Steps:
Smoke test intake [1][7]
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## Car Maintenance Terms
### ABS (Anti-Lock Brake System)
– Purpose: Prevents wheel lockup [7]
### ECM/ECU (Engine Control Module)
– Responsibility: Monitors sensors [7]
### Powertrain Elements
– Contains: Drive axles [7]
—
## Repair Process Steps
1. **Initial Diagnosis**:
Perform visual inspection
2. **Component Testing**:
Test continuity
3. **Parts Replacement**:
Follow torque specs
4. **Final Quality Check**:
Confirm warning light reset
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Diagnostic Scanner | Autel | Live data streaming |
| Hand Instruments | Smoke machine | Electrical testing |
—
## Service Information References
### Auto Repair Source
– Features:
TSB access [8]
OEM specifications
### Digital Assistants
– Vehicle Service App:
Electrical diagrams [5]
—
## Budget Repair Strategies
– Regular maintenance prevents major failures
– Master code scanning to avoid unnecessary repairs
– Install quality alternatives when OEM prices prohibitive [7]