Emissions Headache

[turboherb]

i have a 2003 gmc sierra 1500 sle 4.8, the code i'm getting is p0446.according to my book it is a EVAP VENT SYSTEM PERFORMANCE issue. i have changed the vent solenoid down by the fuel tank twice and also i changed the fuel cap.is there anything else i am missing,its giving me a headache.the code still comes back after i clear them. please help

[Duelin]

i have a 2003 gmc sierra 1500 sle 4.8, the code i'm getting is p0446.according to my book it is a EVAP VENT SYSTEM PERFORMANCE issue. i have changed the vent solenoid down by the fuel tank twice and also i changed the fuel cap.is there anything else i am missing,its giving me a headache.the code still comes back after i clear them. please help

 

 

P0446 GM Definition

 

 

EVAP vent system performance

– The FTP is less than -2.0mm Hg(-1in H2O) .The ECM detects a large leak in the EVAP system.For more than 4 seconds

 

Probable Cause

 

1. A damaged EVAP vent valve ,A damaged EVAP canister

2. Pinched or restricted EVAP vent hose

3. FTP sensor

 

 

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P0446 Generic Definition

 

EVAP (Evaporative Emission System) purge/vent solenoid circuit condition

– The solenoids and system wiring are monitored for opens or shorts

 

Probable Cause

 

1. Purge or Vent Solenoids defective

2. Check connector and wiring

3. Fuel saturated vapor canister

4. Failed EVAP Vent Solenoid