05 blazer
#2
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Is this a Blazer with a 4.3L V6, or a Trail Blazer with a 4.2L inline 6?
Could be any one or more of the following:
Faulty canister purge solenoid or vent solenoid, (just because it's new, doesn't mean it's good).
Plugged EVAP canister, (happens when the tank is overfilled).
Fuel tank pressure sensor.
Poor electrical connection or short circuit, with an EVAP component.
There have been cases where a piece of charcoal, from the canister, will make its way to the purge solenoid and hold it open causing the P0496. You can replace solenoids all day long and keep getting the same result, until the canister is replaced and the lines are cleaned out. All it takes is one little piece, about this size > ' If the solenoid doesn't seal 100%, P0496 will set as soon as the EVAP monitor runs its tests
Could be any one or more of the following:
Faulty canister purge solenoid or vent solenoid, (just because it's new, doesn't mean it's good).
Plugged EVAP canister, (happens when the tank is overfilled).
Fuel tank pressure sensor.
Poor electrical connection or short circuit, with an EVAP component.
There have been cases where a piece of charcoal, from the canister, will make its way to the purge solenoid and hold it open causing the P0496. You can replace solenoids all day long and keep getting the same result, until the canister is replaced and the lines are cleaned out. All it takes is one little piece, about this size > ' If the solenoid doesn't seal 100%, P0496 will set as soon as the EVAP monitor runs its tests
![Wink](https://blazerforum.com/forum/images/smilies/wink.gif)