69gaugeman

Unless they are plugged up, worn out cats will not affect the running at all. If oil is being consumed that will plug up the cats.

It certainly sounds fuel delivery related. There are threads on here showing how to do a quick test by removing fuses for the pumps.

Measuring fuel pressure will show for sure if it is an issue.

stv

I have decided to put vehicle into dealership tomorrow to get checked out.
I will post an update when i get it back.
Thanks for everyone's input.

stv

Ok so I'm picking my vehicle back up again tomorrow after the mechanics have had it for over 1 week now and cant find anything wrong with it apparently.
so its back to the drawing board for me.
My next diagnosis is going to be a fuel pressure test but i need to first purchase a fuel pressure test gauge and wondered if anyone could recommend a pressure testing kit suitable for use with the cayenne.
I have looked at various ones online but from what i have read about the cayenne the connections on the ends of the fuel rails are not standard.
I'm located in UK so a UK company would be best for ordering from if anyone knows.
Also if i need some type of adaptor to fit the fuel rails, where would I get this from?

looking forward to some replies here.

clubracer6

Did you ever figure this out? Sounds like an issue I have and am discussing in my thread here. Been suggested it's a fuel pump, which makes sense to me.

stv

Hi, I never got to the bottom of this yet.
Most of the time my vehicle runs reasonably smooth.
I tried pulling fuse 14 for fuel pump and started car and it idled fine then I tried pulling fuse 13 and started car and it idled fine also, so this has now ruled out a broken fuel pump although I still need to do a fuel pressure test to confirm fuel pressures and fuel volume so I know for sure. If I can find a thread for information on this I will test and post results. If all comes back fine then the only thing I can think of next would be a vacuum leak somewhere that I can not see or an electrical issue. My engine cel light always comes on and throws codes p2177 and p2179 indicating a lean issue at banks 1&2 so I am fairly sure if it's not the fuel then air is getting in through a broken hose somewhere but trying to find this is not easy.

clubracer6

Bummer, I think my fuel pump is original w/151k so it's the leading suspect for sure. Mine has never thrown a code.

Keep us posted.

basadan

First I'd have a smoke test for leaks, the least expensive option.

I had a very similar issue, you should probably test the MAFs are working as cleaning may not work. ECP sell new genuine Bosch or reconditioned units, and also available from GSF. The recon units are refurbished by a non Bosch agent and apparently can be good or bad, much cheaper but more risky. I bought new as it was a royal PITA to get them off in the first place.

From there I'd go fuel filter which gets clogged and would normally be replaced at the same time as pumps.

stv

The garage i put my vehicle into apparantley tried replacing one of the MAF's as they said both sides were reading slightly different but that made no difference they told me and so they changed it back again.

Im going to have a better inspection of all the vacuum hoses once the weather improves here and see if i can find a leak.

Kikokiko1976

Hi, any updates on you problem? Im trying to chase the same error code for 2187/89

Champalwayswin

Hello, i know this is old but I'm having misfire problems. Misfires codes on multiple cylinders.
My question is that your misfire was gone after you changed the purge valve?

MachinegunT

These forums are so valuable! Wish everyone would comeback from facebook so we have archived problem solving post!