Hey Guys...run across a problem and my mechanic either can't or doesn't want to pinpoint it. This is a 2006 A4 stock 2.0T MT6..no mods at all.

Symptoms: Surging while on highway, RPM's while in neutral occasionally rise on its own, when gas cap is removed, car hesitates to start, gas mileage is going down.

CEL came on a few days ago...codes pulled :
P2261-008 (N249 valve Implausible Signal),
P0507-001 (Idle Control System:RPM Higher than expected)
P2187-004 (System is too lean at idle)
P310B-004 (Low Pressure Fuel Regulation)--this may be triggered when I fueled leaving the engine on
P1093-008 (Fuel Measuring system Implausible Signal)

After doing research on here...I'm leading into a failed N80 (Evap Purge Valve) as well as a possible DV valve...the DV is original, and from what I am hearing fails frequently on older units...

Any thoughts/advice? Am I heading in the right direction? How difficult is it to replace? I have a bently manual so hoping it's all directed out for me on there....

 

there is two possible problems since you have a fuel system fault which will cause the surging. possible low fuel pressure sensor gone bad( most likely the proble) next possible is the cam bucket wore out on the high fuel pressure pump and the cam lobe wore out. i would start with the low side fuel pressure sensor first.
P310B-004 (Low Pressure Fuel Regulation)--this may be triggered when I fueled leaving the engine on
P1093-008 (Fuel Measuring system Implausible Signal)

 

P0507-001 (Idle Control System:RPM Higher than expected)
P2187-004 (System is too lean at idle)
these to faults are most likely cause by a faulty crankcase ventalation valve.
run the engine and try to removed the oil filler cap if you cant remove the cap
and it feels like its stuck you have a faulty valve.
do you have any oil around the filler cap area as well.

 

P2261-. 008 (N249 valve Implausible Signal. this could be from a faulty recirculation vavle for the turbo. its bolted to the turbo by three bolts remove it and see the rubber seal on the inside its seperating anywhere.
i would start with the other two causes first.

 

Thanks for your responses....No oil around fill cap and cap is removed easily. I figured also if oil was coming out that I would have smelled it over the course of driving..maybe not but still..clean as a whistle around that area. After talking with a bunch of VW GTI peeps with the same engine...leaning towards a faulty boost valve. This valve is notorious for having a diaphragm that breaks down and it seems to cause similar symptoms and codes. Going to swap that out as I probably need a new one anyway and it is pretty much as easy as you described...3 bolts and a connector and it's off from under the car. I'll let you know what happens as I've already ordered it..comes in time for weekend tinkering.

 

thats good te hear about the oil which means your crankcase valve should be good. replace the valve and see what happens and if the fuel fault codes come back after replaceing the valve i would bet on the low fuel pressure sensor i see those go all the time on a4's let me know what happens

 

Changed out the Boost valve this weekend and MAN can I tell a difference. I still have a faulty evap purge valve...but changing out the boost valve made such a difference that I am glad I did it....

 

I tell everone all the time and it's also in my sticky up top that everone should read. Chances are your PCV is shot as well and BSH is the ONLY one I would recommend.

 

Changed out EVAP purge valve this weekend. Couldn't find the correct one for our B7, but found one for the B6. Installed it (flow direction is reverse the original, so pay attention to the arrow if you also go this route). $60 bucks after shipping and problem is solved! DONE!

 

Is the arrow suppose to face towards the engine or away from it? I just put in a new purge valve that I purchased from ECS turning and its smaller in size than the Original. The Original didn't have an arrow either, so I am curious if its going the right direction?