## Common Diagnostic Trouble Codes

### P0420 Catalyst System Efficiency Below Threshold

– Common Causes:

Exhaust leaks [1]

– Suggested Repairs:

Replace catalytic converter https://carautorepair.site/

### P0171 Air-Fuel Ratio Error

– Potential Issues:

Fuel delivery problems

– Testing Procedure:

Inspect injectors [1][7]

## Car Maintenance Terms

### Skid Prevention Technology

– Function: Maintains steering control [7]

### Engine Management Unit

– Role: Manages fuel injection [7]

### Powertrain Elements

– Includes: Drive axles [7]

## Service Procedure Stages

1. **Initial Diagnosis**:

Perform visual inspection

2. **System Verification**:

Measure resistance

3. **Defective Unit Swap**:

Clear error codes

4. **System Validation**:

Test drive vehicle

## Necessary Equipment

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

|—|—|—|

| Code Reader | BlueDriver | Retrieve DTCs |

| Physical Equipment | Torque wrench | Component repair |

## Repair Documentation Sources

### Auto Repair Source

– Features:

Component locations [8]

OEM specifications

### Digital Assistants

– Vehicle Service App:

ECU pinouts [5]

## Budget Repair Strategies

– Preventative service prevents major failures

– Learn basic diagnostics to avoid unnecessary repairs

– Install quality alternatives when OEM prices prohibitive [7]