## Typical Automotive DTCs

### P0420 Emissions Control Malfunction

– Frequent Reasons:

Exhaust leaks [1]

– Suggested Repairs:

Diagnose fuel trim https://carautorepair.site/

### P0171 Air-Fuel Ratio Error

– Possible Defects:

Vacuum leaks

– Testing Procedure:

Smoke test intake [1][7]

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## Car Maintenance Terms

### Skid Prevention Technology

– Function: Enables safe braking [7]

### ECM/ECU (Engine Control Module)

– Responsibility: Controls ignition timing [7]

### Drivetrain Components

– Contains: Drive axles [7]

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## Mechanical Fixing Workflow

1. **Initial Diagnosis**:

Perform visual inspection

2. **System Verification**:

Measure resistance

3. **Defective Unit Swap**:

Use OEM parts

4. **Final Quality Check**:

Confirm warning light reset

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## Essential Tools

| **Tool Type** | **Examples** | **Purpose** |

|—|—|—|

| Code Reader | Autel | Live data streaming |

| Physical Equipment | Smoke machine | Electrical testing |

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## Repair Documentation Sources

### Mechanical Information System

– Capabilities:

Component locations [8]

OEM specifications

### Smartphone Tools

– Auto Repair Documents:

Electrical diagrams [5]

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## Budget Repair Strategies

– Preventative service prevents major failures

– Understand DTC meanings to prevent mechanic overselling

– Use aftermarket parts when budget constrained [7]