Manufacturer-specific (Ford: EGR Calibration Fault; Honda: Cylinder 3 Misfire)
The P1303 code means the vehicle's onboard diagnostic system has detected: Manufacturer-specific (Ford: EGR Calibration Fault; Honda: Cylinder 3 Misfire). This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- hard
- Estimated cost
- Varies — depends on the specific component this manufacturer-specific code points to on your vehicle. Diagnose before buying parts.
Manufacturer-specific code. P1303 is a manufacturer-specific DTC, so its exact definition can differ by make, model, and year. Use the meaning above as a general guide, and always confirm it against your vehicle manufacturer's official service information (or a make-specific scan tool) before diagnosing or replacing parts.
What Are the Symptoms of P1303?
- Check Engine or a related warning light on
- Exact symptoms depend on the specific system this code covers for your make
- A make-specific scan reveals which subsystem and circuit is involved
What Causes P1303? (Most Likely First)
- A fault in the specific component or circuit this code monitors (the exact part varies by manufacturer) High
- Damaged wiring, a corroded connector, or a poor ground in that circuit Moderate
- A related sensor or control module reporting or causing the fault Moderate
Can I Still Drive with P1303?
No — stop driving. P1303 is rated critical severity. Continuing to drive in this state risks further damage — get it looked at before your next trip.
Frequently Asked Questions
Does P1303 mean the same thing on every vehicle?
No. P1303 is a manufacturer-specific diagnostic trouble code, so its exact meaning varies by make, model, and year. Always confirm it against your vehicle manufacturer's service information before diagnosing or replacing parts.
What does P1303 most likely indicate?
Manufacturer-specific (Ford: EGR Calibration Fault; Honda: Cylinder 3 Misfire). Treat this as a general guide and verify the specifics for your vehicle.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P1303?
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Confirm your exact make, model, and year first — P1303 is manufacturer-specific and can mean different things across brands.
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Read P1303 with an enhanced/make-specific scan tool and check your manufacturer's official service information for the precise definition and procedure.
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Inspect the wiring, connectors, and grounds for the indicated circuit before replacing any part.
Which Vehicles Commonly Get P1303?
- 1998-2005 Toyota Camry V6
- 2000-2006 Toyota Corolla
- 2001-2007 Toyota Highlander
- 2000-2004 Toyota Solara
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