## Typical Automotive DTCs

### P0420 Catalyst System Efficiency Below Threshold

– Frequent Reasons:

Exhaust leaks [1]

– Recommended Fixes:

Diagnose fuel trim https://carautorepair.site/

### P0171 System Too Lean

– Likely Problems:

Faulty MAF sensor

– Testing Procedure:

Inspect injectors [1][7]

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## Car Maintenance Terms

### Electronic Braking System

– Purpose: Maintains steering control [7]

### ECM/ECU (Engine Control Module)

– Role: Monitors sensors [7]

### Powertrain Elements

– Includes: Differential [7]

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## Mechanical Fixing Workflow

1. **Problem Identification**:

Scan DTCs

2. **Component Testing**:

Check voltage

3. **Defective Unit Swap**:

Clear error codes

4. **Final Quality Check**:

Confirm warning light reset

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## Necessary Equipment

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

|—|—|—|

| Code Reader | BlueDriver | Retrieve DTCs |

| Mechanical Tools | Smoke machine | Component repair |

—

## Repair Documentation Sources

### Auto Repair Source

– Features:

Component locations [8]

Factory repair procedures

### Digital Assistants

– Vehicle Service App:

Electrical diagrams [5]

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## Affordable Maintenance Advice

– Preventative service avoids costly repairs

– Understand DTC meanings to prevent mechanic overselling

– Select certified components when OEM prices prohibitive [7]