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Emissions Component

Chevy Tahoe trouble codes P0449 & P0455 Evap Leak - Possible EVAP Vent Solenoid Malfunction.

2007 Chevy Tahoe V8 P0449 & P0455 Evap Leak. TSB related sensor relocation. Check engine light was on. Took it to dealership. They repaired the fault, but the check engine light came back on. I don't know if the check engine is related to the first time or not.


Trouble Code P0449 Definition: EVAP (Evaporative Emission System) purge/vent solenoid circuit malfunction.

Probable Causes

1- Purge or vent solenoids defective

2- Loose EVAP system connectors and/or wiring

3- Failed EVAP vent solenoid

4- Failed Gas Cap

If you have replaced the gas cap once and P0449 came back this means there is an issue with the EVAP canister vent valve located near the EVAP canister and the fuel tank. P0449 typically indicates the solenoid on the EVAP canister vent valve is not receiving the proper voltage and or ECU signals.

Trouble code P0455 is related to:

1. A loose or improperly affixed gas cap

2. A non-conforming gas cap (i.e. not factory/original brand)

3. Other leak or damaged component in EVAP system

With a P0455, the most common repair is to:

Remove and reinstall the gas cap, clear the codes, and drive your Tahoe for 100-200 miles and see if the trouble codes reappear.

posted by SmogTips Support 11-22-2011 03:56 AM