I just finished doing the intake manifold seal replacement and now I am getting a DTC 441 code (EVAP) I have checked all the vacuum lines and electrical connections and they are in good condition. Before I did the work I had never seen this problem, any idea what the most likely culprit is?

 

Ok few more things I have checked now:

1) No apparent charcoal in the lines.

2) I disconnected the vacuum switch and the two electrical prongs(connector) give a closed condition (0 resistance) when I apply a little suction using a rubber hose and plugging the other side, it goes into closed condition (infinite resistance) So from what I am reading that appears to be working fine.

3) I applied 12 volts to the solenoid and it went from normally closed which I checked with a little rubber hose and gently sucking on it to open condition so I guess that is working fine.

When I suck on the hose going to the gas tank I appear to get no resistance, is that how it's supposed to be?

Now that I have checked to solenoid and valve separately what is the best way to check to see if they are working with the car running?

 

According to my OBDII tech book, the 441 can be caused by:

Vacuum leak
Cracked vacuum line/plastic connector
Vacuum switch
Plugged hose from solenoid to cannister or throttle body

It also implies the vacuum switch is usually the #1 suspect.

 

Thanks moparman!

Well I found the problem! the line from the solenoid to the TB was plugged and even though the solenoid came on it never saw any vacuum. Now I am out to test drive it