Bad Harness causing gas tank problems???

[knicksplayer]

Hi everyone,

I brought my 02 Porsche boxster to the dealer because I got a P0455 CEL Large Leak (Evap) check engine code. The front part of my harness (near the right side
turn" indicator) is in bad shape and the mechanic claimed that may be the problem. I felt he wasn't confident in what he was saying and given that the harness change costs like $4,000 (that's what he quoted!!!), I feel he's trying to play me. The bad harness causes my abs and psm lights to be on and after testing the car in extreme situations, it doesn't cause a safety issue. Anyways, back the EVAP problem, my gas tank spits back fuel and I think it would imply that it's simply a bad EVAP and that the engine check indicator therefore makes sense?? Does anyone know what exactly would have to be done if that was the case? I changed the fuse, the problem isn't that simple (I wish) and I don't hear that clicking sound when I push the metal flap out of the way. But what I do hear is some kind of air coming out of the tank when the metal flap is slightly open? That would explain the problem by law of physics, the air/vapor would be the cause of the fuel spit...

So that's about it, that's the story, any comments will be appreciated. Thanks!

[extanker]

how many warning lights are on ? codes ? wiring bad ? how ? wires chaffed etc ?

[knicksplayer]

Only one code, that EVAP (large) one. I have three warning lights on the dashboard (ABS, PSM, BREAK) but breaks have been replaced and tested. These lights actually come on a few minutes after you start driving the car. Oh and I have the engine check light which is on as soon as you start up the car. The wires seem to be cut or worned out by some friction, I am not the first owner of the car and sadly never saw that issue before.

[idheaton]

For your dash lights it could be something as inexpensive and easy fix yourself as a bad igntion switch or a bit more expensive and less easy to diy, your alternator going out, luckily the alternator is easy to diagnose if you have a multimeter.

The p0455 code and hard to gas up could either be a bad purge valve, shutoff valve or EVAP cannister.

I also seem to recall some fill tubes that could possibly be slipped or tweaked that would cause the gas problem but I am not sure which years that this might affect. I am not sure if this would cause throw a code either.

Approximate prices not for the items, not including labor, to fix the above issues are:

Ignition switch: $20-25
purge or shutoff valve: $100
EVAP cannister: $150 - 275 depending on which cannister your year uses. The more expensive one actually comes has an opening for the purge valve and includes it along with what I think was a vent tube while the less expensive one does not include either nor fittings to accept them, it is just the cannister with different tube attachment points. Don't ask me how I know...

Changing the cannister and/or valves is a easy operation to do. You just need to remove the passenger wheel and wheel well liner and you will see them to the rear of the wheel well. Once you get the wheel off, the only other tools you will need are a flat tip, phillips and a rachet and socket (i forget which size) for the RNR of the rest. I think it took me around a 2-3 hrs to change my cannister.