Fuel System Leak Test
WARNING: This page is about a different car, the 2016 Audi A3 and 2015 Audi A3. However, it is still accessible from the selected car via links, so may be relevant.
-- Let the engine run at idle for a few minutes. Do not use accelerator and then stop the engine. The fuel system bleeds itself.
-- Check the entire fuel system for leaks.
-- Replace the part if there are leaks in spite of correct tightening specifications.
-- Perform a road test and press the accelerator pedal all the way down at least one time.
-- Check the high pressure system again for leaks.