i have a 98 gmc sierra 1500 pickup and the service engine is reading evap...

[Lindsay]

...PO446 what part needs to be replaced? I had 2 mechanics tell me two differnt things one said the purge valve on the engine the other said its a canister under or NY the fuel tank? When the truck runs to long it doesn't read hot but after a few miles it bogs out and the more I push the gas or down shift or vice versa it starts bogging out and sputtering!
oops P0446, thankss.... i hate the t9 feature on my blackberry..im lucky i can get anything typed.

 

[mrlavocat]

Both could be right, however the most likely problem is a simple vacuum leak somewhere between the fuel tank, purge valve, evap canister, and intake. At any rate you should inspect all the vacuum lines first before replacing anything.

And the code is p0446, not po446.

 

[Michael S]

Here you go.....

http://www.gmtruckclub.com/forum/showthread.php?18964-Quick-fix-for-code-p0446-evap-emissions-vent-circuit-low.

it shouldn't cost more than $50 if the mechanic is a crook. $25 if he is honest.
Copy the page in the link and show it to the one you trust the most, or find someone else to do this. It really looks and sounds simple.