What does code P0455 mean on a Pontiac and is it safe to drive?
P0455: Evaporative Emission System Leak Detected (Large Leak). Here's what it means on your Pontiac, 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 Pontiac
- 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 Pontiac, 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.
Known issues on Pontiac
Pontiac P0455 on GM platforms starts with the gas cap. On G6 and Grand Prix, a failed EVAP canister purge solenoid is the second most common cause; it is inexpensive and easy to replace before performing a full smoke test.
Most commonly affected models
G6 2005–2010Grand Prix 2004–2008Torrent 2006–2009