## Common Diagnostic Trouble Codes

### P0420 Emissions Control Malfunction

– Common Causes:

Worn catalytic converter [1]

– Recommended Fixes:

Diagnose fuel trim https://carautorepair.site/

### P0171 Air-Fuel Ratio Error

– Possible Defects:

Fuel delivery problems

– Testing Procedure:

Check fuel pressure [1][7]

—

## Car Maintenance Terms

### ABS (Anti-Lock Brake System)

– Purpose: Maintains steering control [7]

### Vehicle Computer System

– Responsibility: Controls ignition timing [7]

### Drivetrain Components

– Includes: Drive axles [7]

—

## Service Procedure Stages

1. **Symptom Assessment**:

Perform visual inspection

2. **Part Evaluation**:

Measure resistance

3. **Parts Replacement**:

Clear error codes

4. **Post-Repair Verification**:

Confirm warning light reset

—

## Essential Tools

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

|—|—|—|

| Code Reader | Innova | Retrieve DTCs |

| Physical Equipment | Multimeter | Electrical testing |

—

## Repair Documentation Sources

### Auto Repair Source

– Features:

Wiring diagrams [8]

Factory repair procedures

### Smartphone Tools

– Auto Repair Documents:

Component testing guides [5]

—

## Cost-Saving Tips

– Preventative service avoids costly repairs

– Learn basic diagnostics to prevent mechanic overselling

– Use aftermarket parts when budget constrained [7]