P0021

Comprehensive diagnostic guide for P0021 Camshaft Position - Timing Over-Advanced, Bank 1

PowertrainFuel and Air MeteringModerate

Quick Answer

What P0021 Means

Comprehensive for P0021. This affects your vehicle's fuel and air metering system.

Most Likely Cause

Multiple possible causes - see diagnostic details below

Moderate DIY

Many causes can be addressed by experienced DIYers.

Address Soon

Generally safe to drive short-term. Have it diagnosed soon.

Safe to Drive (Short-Term)

Generally safe to drive short-term. Have it diagnosed soon.

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Detailed Diagnostic Information

This diagnostic guide was generated using verified reference data:

  • NHTSA Consumer Complaints: 1 real-world reports analyzed
  • Wikipedia Technical Articles: OBD-II
  • Open-Source OBD2 Data: N/A (MIT)

Content synthesized from these sources to provide accurate, real-world diagnostic guidance.


Consider professional help if:

  • You are not comfortable performing the diagnosis yourself
  • The issue requires specialized tools or equipment
  • Initial repairs did not resolve the code
  • Multiple codes are present simultaneously
  • The vehicle is still under warranty

Frequently Asked Questions

What does code P0021 mean?

P0021 indicates Comprehensive diagnostic guide for P0021 Camshaft Position - Timing Over-Advanced, Bank 1. This is a powertrain code related to the fuel and air metering system. When your vehicle's computer detects this condition, it stores this code and may illuminate the check engine light.

Can I drive with code P0021?

You may be able to drive short distances with P0021, but it should be addressed soon. Extended driving could lead to additional problems or increased repair costs.

How much does it cost to fix P0021?

Repair costs for P0021 typically range from $100-$800, depending on the root cause and your vehicle. Diagnostic fees are usually $50-$150, and actual repairs vary based on whether parts need replacement. Get multiple quotes for the best price.

What causes code P0021?

Common causes of P0021 include sensor malfunctions, wiring issues, mechanical failures in the fuel and air metering system, or related component wear. The specific cause requires proper diagnosis with a scan tool and visual inspection.

Will P0021 clear itself?

P0021 may temporarily clear if the underlying condition improves, but the root cause should still be diagnosed. If the problem persists, the code will return.

Important Disclaimer

This information is for educational purposes only. We are not licensed mechanics. Always consult a certified mechanic for diagnosis and repair. Improper repairs can be dangerous.

Last updated: 2025-11-26

P0021 diagnostic guide by MechanicGPT