What does code P0455 mean on a Hummer and is it safe to drive?
P0455: Evaporative Emission System Leak Detected (Large Leak). Here's what it means on your Hummer, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
PowertrainMedium urgency
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 Hummer
- 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 Hummer, 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.