Intermittent P129B/P2294

A6 All/ S6 All
#1

So as of lately I’ve been having a really strange issue where the car will run like complete ass sometimes…

Sometimes it starts and runs just fine and other times it will run really rough at idle and acceleration. The two codes that always seem to pop up when it does decide to run like garbage is P2294 (ECM 1) and P129B (ECM 2)

I’ve replaced both HPFP’s, the low pressure and high pressure sensors in the fuel rail, as well as the fuel filter. Turning the car off and back on seems to clear the faults and the cars back to rippin’. I’ve looked over all the sensor connectors and can’t seem to find anything out of the ordinary.

#2

Do you have a ross tech vag com cable. Posting the P codes is the first part of getting help but the actual definition is what is going to really get you more help as most people don’t have then memorized.

Also vag com gives you data that can further help give an idea on what conditions the codes came from

#3

I have OBDEleven. Seems to work for what I need. Again, both are intermittent and for the most part the cars a ripper… Usually when I do a warm start it will lean out and the codes will appear. Cycling the key a few times will normally clear the codes out.

P2294 Fuel Pressure Regulator 2 (Control Circuit Open) No signal/Communication

P129B Fuel Pressure Regulator Bank 2 (Open Circuit) No signal/Communication