What does code P0455 mean on a Cadillac and is it safe to drive?
P0455: Evaporative Emission System Leak Detected (Large Leak). Here’s what it means on your Cadillac, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
A large leak has been detected in the EVAP system. Could be gas cap left off, disconnected hose, or damaged canister.
Common causes for your Cadillac
- Gas cap missing or not sealed
- Disconnected or ruptured EVAP hose
- Damaged charcoal canister
- Faulty purge/vent solenoid
Symptoms
- Check Engine Light
- Fuel smell possible
Typical fixes
- Install or replace gas cap
- Inspect and repair EVAP hoses
- Replace canister or valves as needed
Repair cost range
For a Cadillac, repairs for P0455 often fall between $20 and $500, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.