Pontiac Repair: Emissions, fuel filler pipe, vacuum flow

Question
I have a 1996 Buick Regal, 3.8L with a P0441 evap code. I have checked the system and I noticed it will not hold a vacuum. I have narrowed it down to the canister. I bypassed the canister and the vacuum holds. My question is should the canister hold a vacuum using my hand pump?

Answer
Hi Ed:

That emission system on that car was a pull a head system for OBDII it's not an enhanced emission control system. so to answerr your question the canister doesn't hold a vacuum on thos older systems. 1997 and up they do/did. more then likley the issue is with the vacuum flow switch which is in the vacuum line near the rear valve cover. Ir is a round disc with a 2 wire connector on it. that is usually whjat went wrong with that system. The sensor's job was just to detect  a minimal amount of vacuum present when the syetm is purging.. The only other things that happen with the system are if you live in the rust belt like I do the fuel filler pipe rots out on the top and damages the seal on the gas cap But that is a stretch on those older systems The newer ones YES for sure.