kingfishgrapejam

So my new to me 07 S6 with 110k on it threw an EPC warning about a week into ownership along with some stumbling around 6k. No CEL. I bought it from a local audi dealer and it was a local trade. When I went to see the car the first time they had it in a bay with with intake manifold off. Supposedly they decarbed it and replace a coil pack and injector.

My radar went up of course but the maint history was so strong and the price was very good at 21k, not to mention the car is practically spotless. Original owner bought a new for wife has two R8's blah blah.. good stuff.

Back to the story. I fill up with premium and put a bottle of 104 plus in and next 400 hundred miles or so are are flawless...until Tues of this week. Car stumbled at anything past 3000rpm and the EPC light is now my permanent companion.

Upgrade my Vag cable, order a fuel filter. Installed both tonight.. Autoscan turns up Fuel rail pressure too low and misfire on cylinder 8 but the car runs smoothly at low rpm so starvation probably triggered the misfire. By the way the car felt earlier I already have a fuel filter in hand ready to install...on the lift and 20 minutes later with some gasoline in my eyes fuel filter is in. Put the car down and romp around the neighborhood. EPC light came on once during a 2nd to 3rd stumble at 6 grand. shut the car off at the stoplight restart re-romp and no problems since. So I think the fuel filter solved the issue but I am wondering if the main fuel pump may be on it's way out or maybe the EPC instance was due to the car just not being all way warmed up.

Noticed the new fuel filter has 6 bar stamped on it. Old filter was the original. I am hoping to god that the dealer replaced the pressure sensor when they had the manifold off.

Is there a method to check the fuel pumps through Vag?

samg713

Hi, did you ever fix your car? I have the same issue today, my mechanic scanned it and said the pressures seem good so he believes it is a fuel pressure sensor acting up intermittently. Any input would be appreciated

kingfishgrapejam

Sorry, I though I posted the solution. I wound up replacing the low pressure fuel pump which didn't help. Then I replaced both High pressure pumps and that solved the problem. High pressure pumps were pretty easy to replace. Low pressure pump in in the tank so the back seat has to come out but not too terrible of a job either.

AndreNY

when you changed the High Pressure Pumps did you also replace the Cam Followers?

kingfishgrapejam

I honestly can't remember for sure, I remember looking into doing it but think the originals looked perfect still.