I Have an Audi -A4-2.0T Year 2008
One Month Ago I have a message in the dashboard " CLOSE FUEL CAP" I stopped and I re-closed ,But still showing up the same message.
After driving for 1 hour the engine light show up , I put my scanner and I have the following codes P0455/P0456.
I Checked my car for gas smell or leaking beginning with the fuel tank , then underneath of rear seat and in the trunk, I removed the gas cap and re-installed .
I checked the evap leak detection pump and fuel pump control module and I removed the underneath cover to follow the hoses until I got to the purge valve solenoid .
I Replaced the canister purge valve selenoid located at the left rear part of the intake manifold and the engine light disappear , After 45 days the engine light show up again with the same codes and some time these codes " system to rich bank 1 and system too lean bank 1".
I have been noticing when the gas gauge white indicator is in the first line the"CLOSE FUEL CAP" appear , yesterday my car was empty of gas and I filled up ,when i try to started its hesitate like 3 times and finally start ..another thing that i noticed is sometime is lacking of power in the first 20 second and then the force/torque/power is back.
The codes system too lean and system too rich, i know that i should replace the oxigen sensors , but i dont think these will solve the problem ...
Some time I have been adding fuel enhancer/ fuel injector cleaners to my car , can this cause some kind of problem and the sensor are sensing foreign liquid in the gas tank ?