### P0420 Catalyst System Efficiency Below Threshold
– Typical Sources:
Worn catalytic converter [1]
– Common Solutions:
Diagnose fuel trim https://carautorepair.site/
### P0171 System Too Lean
– Possible Defects:
Faulty MAF sensor
– Diagnostic Steps:
Smoke test intake [1][7]
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## Car Maintenance Terms
### ABS (Anti-Lock Brake System)
– Function: Enables safe braking [7]
### Vehicle Computer System
– Role: Manages fuel injection [7]
### Powertrain Elements
– Includes: Drive axles [7]
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## Service Procedure Stages
1. **Problem Identification**:
Scan DTCs
2. **System Verification**:
Test continuity
3. **Component Installation**:
Use OEM parts
4. **Post-Repair Verification**:
Ensure proper operation
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## Essential Tools
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| OBD-II Tool | BlueDriver | Retrieve DTCs |
| Mechanical Tools | Smoke machine | Electrical testing |
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## Service Information References
### Vehicle Service Database
– Features:
Component locations [8]
Factory repair procedures
### Mobile Applications
– Vehicle Service App:
ECU pinouts [5]
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## Budget Repair Strategies
– Preventative service extends vehicle life
– Learn basic diagnostics to prevent mechanic overselling
– Use aftermarket parts when budget constrained [7]