### P0420 Catalyst System Efficiency Below Threshold
– Typical Sources:
Faulty oxygen sensor [1]
– Recommended Fixes:
Repair exhaust system https://carautorepair.site/
### P0171 Fuel Mixture Imbalance
– Likely Problems:
Faulty MAF sensor
– Testing Procedure:
Check fuel pressure [1][7]
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## Car Maintenance Terms
### ABS (Anti-Lock Brake System)
– Function: Enables safe braking [7]
### ECM/ECU (Engine Control Module)
– Role: Controls ignition timing [7]
### Drivetrain Components
– Contains: Drive axles [7]
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## Repair Process Steps
1. **Symptom Assessment**:
Perform visual inspection
2. **Component Testing**:
Check voltage
3. **Parts Replacement**:
Clear error codes
4. **Post-Repair Verification**:
Test drive vehicle
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## Critical Instruments
| **Tool Type** | **Examples** | **Purpose** |
|—|—|—|
| Code Reader | Autel | Live data streaming |
| Hand Instruments | Smoke machine | Electrical testing |
—
## Repair Documentation Sources
### Mechanical Information System
– Features:
TSB access [8]
Factory repair procedures
### Mobile Applications
– Auto Repair Documents:
ECU pinouts [5]
—
## Affordable Maintenance Advice
– Regular maintenance prevents major failures
– Understand DTC meanings to prevent mechanic overselling
– Install quality alternatives when budget constrained [7]