mrbeaubo

Hey guys,

My wife has a 2009 V6. She started getting code P12A2 and had intermittent surging of acceleration, but car still ran okay. Took it to a shop and they recommended changing the fuel pump, fuel pressure regulator, and fuel pressure sensor.

They changed all of that and it didn't fix the problem, the light came back on. Now they are saying it may be something related to the timing chain, but I'm having a hard time understanding how this could be. This is a very reputable shop, I just don't want to throw money after a timing chain repair (See $$$$$$$$) if that's not going to fix it.

Help!

mrbeaubo

Anyone else have this issue?

Diasbrian

Did you ever get to the root cause?

mrbeaubo

Porsche dealer changed the intake gasket and some other areas that may have been sucking in air to cause RPM fluctuations and seemed to fix it.

endless_corners

I wouldn't be too happy with the "reputable" shop replacing parts on your dime and then recommending getting at the timing chain. Seems like they are making a lot of work for themselves.

mrbeaubo

I definitely wasn't happy, ie why I went somewhere else!

mrbeaubo

Dangit this problem is back, same code. Anyone have any ideas? Had the fuel pump, fuel pressure regulator, fuel pressure sensor, valve cover, belt, mass air sensor replaced in 2014 and ran fine until about 3 months ago. Shop just replaced plugs, rear O2 sensors, cleaned throttle body etc. and now I have code with car running great except for a rough idle which sits around 600 rpm. Any ideas? Could my parts have gone bad in 3 years again?

deilenberger

I see no mention of coils being replaced. They're pretty much a maintenance item on the early Cayennes. And what are the actual code readouts? p12a2 means nothing at all. What are the OBD-II readouts telling us? That's best done with a Porsche specific code reader - but even the Autozone free read will be more information than you're presenting us now.

mrbeaubo

I'm just telling you the info I have right now. I'm trying to get it to an independent Porsche shop for full code read and trim numbers. I can grab some other numbers later tonight too on my scanner if possible.

mhariush

did you get any more info on this? My 08 V6 just threw CEL and giving me the same OBD-II P12A2 Code, and I don't have a Durametric accessible. Feels like the car has a vacuum leak though. Bought it on Sunday, drive it a few hundred miles and it was great, then last night it got a different sound to it, and today the CEL came on.

mrbeaubo

Turns out my issue is the catalytic converters. Had shop make sure everything else checked out and car running perfect except for the light. Haven't bothered fixing it because it's super expensive.

mhariush

found this in a trouble codes manual from Porsche.

realFerdinand

So is CEL still off? after all the parts you've replaced to get rid of P12A2. You think ultimately it was the catalytic converter? primary or secondary?
I'm dealing with this code at the moment on my 08 3.6 V6 with 100k miles.

mhariush

from reading more and looking into it, it seems like the most likely candidate is the oil air separator diaphragm but in the 957 you have to remove the valve converter and stuff. So I'll put it on the list to do down the line.

Libast

You can just pop the black cap off and buy a replacement membrane from somewhere like here

http://www.klaindustries.net/diaphragm/air-oil.htm

Porsche will want to sell you the whole thing as an assembly though, you're right on that