audiaza4

So I had CEL 2 weeks ago and it threw codes P0089 and P0455. Last week Dealership replaced the fuel pump, fuel filter, LDP filter, EVAP canister, and EVAP pump filter. Back History: Have had TWO fuel pumps/filter prior to last week's replacement in last 6 months. Grand total is three fuel pumps/filters in six months.

TWO days after all that was done, it threw the same codes again...

Now they tell me it's Fuel Tank Failure for $2800. have seen NO references to Fuel Tank Failure on The Google...

A4Audi4Fun

Sounds like there must be a huge amount of dirt or something that has ended up in the fuel tank somehow. How old is the car? What's been the history for the fuel type/source that's been used? Did the car sit in storage for an extended time?

s4master1

I personally think your problem is the dealer you are using, but I wish you can get more info before i can assert this.
how is the fuel pressure flow?, constant, erratic?
1st, 2nd and 3rd pump readings?
what is the vacuum/pressure in the tank while at idle? does it change with throttle opening?
MAF readings, g/s?
I would double check the purge valve and also make sure is installed correctly as it can allow vacuum from the intake manifold to the tank collapsing it and causing erratic fuel pressure causing the first fault code P0089.
as this happens it also stays open causing lean mixture and evap faults P0455.
they may be right but after 3 pumps sounds questionable.

audiaza4

Many thanks, brother!!!!