2000 Boxster S 130,000 miles that I bought a few weeks ago. It has these symptoms:
-Near impossible to add fuel from a gas pump. Even on the first click, fuel backs up and goes down the drain in the filler neck (presumably to the charcoal canister.
-Both evenings after I've added fuel, hours later I got the "coke bottle" howl from the fuel filler area with engine running followed immediately by a check engine light and a P1128 code.
It sounds like every description I've seen of a bad tank bleeder valve (
996-201-143-01)... but, I know the reed switch and the valve are at least partially functioning. First of all, I can hear it click when I push in the flapper. I also know it's at least partially venting because when I had the battery disconnected I tried to add fuel from a jug and it wouldn't accept the fuel even at a very slow fill rate. I reconnected the battery, could once again hear the valve click and I was able to successfully add 5 gallons of fuel from a jug without issue.
I'd hate to replace that valve for over $200 and have it not be the problem. How do they typically fail? Do they ever partially fail like this where they can sustain a very slow fill rate but not open far enough to accept gas pump flow rates?
I've also read anecdotal accounts that this could be the "Purge Valve for Fuel Vapor Canister" ($102), the "Fuel Tank Vapor Valve for Carbon Canister" ($337) or even the "Regeneration Valve from Throttle Body for Fuel Vapor System" ($48). I'd really prefer not to throw expensive parts at it but I don't have a very good understanding of how it all works to do intelligent troubleshooting. I also suppose the howl and the difficulty fueling are related but separate issues. The tank bleeder valve may not be open completely or the hose partially obstructed and then I'm just dumping a lot of fuel into the charcoal canister via the drain when it overflows which triggers one of the other faulty valves to open or close inappropriately later?