Help with O2 / Evap DTCs - 986 Forum - The Community for Porsche Boxster & Cayman Owners

My '00 2.7 Base 5spd and I have a date with the Blue Ridge Parkway in about 3.5 weeks. I have recently started getting a couple of strange symptoms, and have read a LOT of different explanations/fixes for similar circumstances on various forums, but nowhere have I found my exact set of circumstances. Codes and symptoms at the end... So, here we go: I got my first CEL a couple months ago while driving down a country road in GA in the middle of nowhere. Some a-hole was tailgating me so bad in a big hoopty that I couldn't see his massive gold grille, and this distracted my attention. Long story short I drove about 5 miles at ~60mph in 2nd gear (I have 19" rims and I can get close to 70mph without over-rev, not that I would ever do that on purpose). Still though, I was driving in the 6-6.5k rpm range. Had the top down and was so busy yelling obscenities and watching the rearview I didn't notice the engine noise. So ok, I take my foot off the gas and realize from the rapid decrease in speed what an idiot I've been...shift into 3rd/4th and continue about my merry way. CEL comes on within a couple of minutes, and turns itself off somewhere in the remaining 35-40 miles to home. About a month after that, I got another CEL while parking at work. This one stayed on, so after about a day and a half I hook up the computer and it's got 3 or 4 codes, none in last drive cycle. I record them, reset them, continue. 3 or 4 more times since then I get CEL usually when idle or barely moving after driving at 55-70mph for a few miles, which I do daily on my way to work. The codes come up 1 or 2 at a time, and have been a total of (4) different codes: P0440 P0446 P1114 P1115 2 of those are O2 sensor codes and the other two are evaporative emission control system errors if I got the right list here. Here is maybe the most definitive symptom of all though, which from my reading about those codes and problems/fixes may be the smoking gun: any time I put gas in the car, whether it be a few gallons or full tank (though seems a little worse when I top it off), the car will not start right up. The starter will fire up just fine, and there is plenty of electrical power, but the only way to start the car is run the starter for just a litle bit unreasonably long time. About the time all the people at the store start staring at me and laughing inside about that rich a-hole's bada$$ car won't start, it fires up. Everything is running but it's either no spark or more likely, no fuel. Eventually it gets in there and blammo - roar - we got power houston. I can then turn off the car, reset the ignition and crank it right back up just seconds later without hesitation. This has not happened EVER when I did not just put gas in. No, I do not have an aftermarket locking gas cap. Porsche OEM - Drehen Bis Click! So, I've heard everything from replace all the O2 sensors, to replace the gas cap, to flush out some little valve, and a bunch of things that make less sense than those. In the interest of my upcoming trip in which I plan to roll 1500-2000 miles on it in a week, I want to make sure that a) the car is going to get me there, haul major arse all over the mountains, and get me home, b) that it will do it in high-performance style, and c) that I'm not damaging additional parts by whatever this is. So I want to get this worked out before I go if possible. The people who seem most knowledgeable on some forum posts I've read about similar issues say "start replacing parts until you stumble upon the fix." Well I can't tell if I've fixed this or not by replacing a bunch of parts because it only happens maybe once every 2 weeks, and the DTC(s) will only come up for one individual cycle, then not recur for another couple weeks. Ideas? Suggestions? (can't afford to just replace the whole thing with a 3.4 or I might already have done so, so skip that one).

Couple more details - I have monitored and logged O2 sensor and MAF data while driving and all O2 sensor readings have been within spec. I don't know off the top of my head what spec is for the MAF, but I can at least say that the readings are consistent from one trip to the next, and that I remove and clean it and everything around it about 3-4 times a year because I'm running a K&N air filter.

PM sent. Regards, paul...

New symptom just manifested itself, and when I say 'new' I mean I haven't noticed it before, not that it necessarily hasn't happened before. I just topped off the tank. It took 12.6 gallons about ~8-10 miles after the gas light first illuminated. Again it took about 30 seconds of running the starter to fire up, and it idled a little rough until I put it in gear. Driving off from the gas station, I noticed the fuel gauge as pictured. Is the fuel level sender vacuum based? Everything else seems consistent with a vacuum problem. Just for due diligence, I did swing back around by the petrol station and confirmed there was not a couple gallons of premium on the ground, no giant flammable puddle in the car, etc. I drove another 6-7 miles home and no increase in fuel reading. I got some really good troubleshooting advice already, but before I go running all that down, if this indicates anything more specific and might save me some time and or money, I sure would appreciate it. (Click image for big version)

Ok so here's where I am now. I went ahead and removed the evap canister...makes getting to those hoses quite a bit easier and it was just the one 10mm nut to remove. Duuuh..wish I'd tried that sooner. I was able to finally find the valve in the line under the dead center of the driver's side manifold. I have looked right at it 100 times but due to the angle my car is sitting at right now and lighting etc, I just missed the valve. Finally put my gloves on and started feeling around, found it in 10 seconds. From that valve, the hose runs around to a Y connector just forward of the MAF - the other end of that looks lke it goes in to the air/oil seperator thing. Question is, for the blowout test (for hose continuity), do I want to disconnect back there at all, and if so, do I need to disconnect before that impossible-to-get-to valve, or pull the hose on the other end of that off of the Y connector on the intake? Something else?