2020 Mazda CX-5 P0456: Very Small EVAP Leak Repair

P0456 on Your 2020 CX-5: Following the Clues

Your 2020 CX-5 has triggered P0456—a very small EVAP leak. The 2.5L Skyactiv-G uses a standard EVAP system. Basic warranty expired, but federal emissions (8yr/80k) covers through 2028.

Clues

• Check engine light on
• P0456 stored
• No performance symptoms
• Gas cap may show wear after 5+ years

Suspects

1. Gas Cap Seal (High Likelihood): Five years of wear. $10–$15.
2. Purge Solenoid Valve (High Likelihood): Age-related. Under emissions warranty or $80–$180.
3. Canister Vent Valve (Medium Likelihood): Wear. Under emissions warranty or $90–$200.
4. EVAP Hose (Medium Likelihood): Rubber deterioration. $100–$210.
5. Charcoal Canister (Low Likelihood): Fuel overfilling. $180–$340.

Diagnostic Steps

1. Replace gas cap—$10–$15
2. Clear code, drive 2–3 cycles
3. Check federal emissions warranty—8yr/80k through 2028
4. Mazda dealer or independent shop
5. Smoke test if needed ($80–$130)

Costs

• Gas cap: $10–$15
• Purge valve: $80–$180
• Canister vent valve: $90–$200

Can I Drive?

Yes. P0456 has zero impact on the Skyactiv or AWD.

Warranty

Basic 3yr/36k expired. Federal emissions 8yr/80k covers EVAP through 2028.

Frequently Asked Questions