GBD1

I have a 2010 Audi A4 2.0t with the code P2279 I replaced oil separator, Trhotle body gasket, Mass Air Flow Sensor still have the same codes check system for vacuum leaks with smoke machine no leaks were found vehicle start and hesitates any time it wants not all the time few days work like a champ then for no reason it start hesitating and brings back code P2279 other days it just bring code P2188 System too rich at idle Bank 1 when connecting scan tool LTFM -42 STFM -25 then after 20 minutes or more at idle the LTFM goes to 3.95 and STFM go to 0.8 moving up and down few numbers but not much in like perfect scenario

slonela

I have the same issue with these 2 codes (P2279 and P2188) now for about a year now. P2188 show up more often tho. for me. I am guessing for me it is related to coolant system. I am in Michigan and do not have issue when the weather is cold. But it is showing up again now that weather is in the 60s. I have a long commute to work which is a lot freeway than local. So I am guessing the engine is getting too hot and does not have enough time to cool off.

I am planning on getting a coolant flush next month along with replacing coolant temp sensor. I am at about 145K miles now.

Would like to know also if anyone was able to figure out the root cause.

Ladeitz

I would try replacing the Fuel Filter, it is the easiest/quickest and least expensive if you are strapped for cash.
Make sure you are only putting 93 Octane in your vehicle.
Those codes that you are getting, look like they are just codes getting flagged due to the engine shutting off unexpectedly.
After you change your Fuel filter, if the problem still happens, I doubt it is the actual pump. it seems like it could be that you need a tune up performed on the car, since it is happening at low rpms.