CEL - P0446?

[andygr2000]

Hi

I have a 2000 Boxster with 55k miles. Yesterday the CEL came on while on the way to the office, I drove it home later in the afternoon without any incident until I stopped for gas. The car would not start after the fill-up, engine cranks OK and everything seems normal but no firing. Walked over to a garage next to gas station to borrow OBD-II reader, got the code P0446. Found that P0446 relates to EVAP Canister Shutoff Valve (Function) - Below Lower Limit. Long story short, waited an hour, the car started "normally". :clapping:

Called the local independent Porsche mechanic for an appointment but could not get in until later this week or early next week. The mechanic mentioned there may be some sensor failing but car can be driven until I can take it in. Any thoughts to the P0446 and the mechanic's suggestions? Is this something that an 'average' person can fix without taking to the shop? Thanks in advance

[Loren]

The OBD II manual says (for Fault P0446) the possible cause are:

- Purge air line blocked.

- Flow resistance of EVAP canister too high.

[andygr2000]

Thanks Loren. I suspect the repair will have to be done in a shop since I read somewhere in PCA Tech Library that repairing/replacing the purge air line is quite involved. I'll update if/when CEL comes back on with additional codes.

[andygr2000]

Update to CEL P0446.

CEL came back on next day, which is a good thing since this will give the technicians something to reference when I was able to take it to a shop yesterday. The technician checked the CEL and found fault codes: P0446; P1128 and P1130. Checked and tested the purge air line but did not find any blockage, found an oil leak onto the top of engine block. Did not find leak from the usual suspect "oil filler tube", he did find a loose vacuum line under intake manifold which was re-connected. Reset CEL and car ran fine since... well, it has been only a day and driven less than 50 miles. His diagnosis is the oil seperator may be going bad. We'll see if the CEL comes back on. Any thought to the oil seperator? Car ran fine and did not have any smoke on exhaust. Thanks for all your input.

[andygr2000]

The saga continues...

After replacing A/O Seperator, CEL came back on with same P0446, P1128 and P1130. Took car back to dealer, diagnosed tank vent valve cracked and tank purge valve inoperative. Replaced following parts:

996-605-213-01 Carbon Cont Valve

996-110-120-05 Air Vent Line

Car ran fine for a day, CEL with P1128 and P1130 came back on next day with hunting idle. :censored: Will be taking it back in to dealer next week.

[andygr2000]

...

Car ran fine for a day, CEL with P1128 and P1130 came back on next day with hunting idle. :censored: Will be taking it back in to dealer next week.

Turns out that this instance of CEL P1128 and P1130 was due to cracked intake manifold. Following part was replaced:

999 110 686 01 - a $13.00 part / 1.50 hr labor.