It is 2001 Corolla 1.8 engine. I'm still in the process of diagnosing an intermittent P0171 code. I posted a video in other post and user Carguy was very helpful and he mentioned that this ticking sound not normal and asked me to check where is it coming from and found it was the purge valve clicking constantly after the engine gets warm on idle. I went to a junk yard and got a used one for cheap just to make sure that i don't have a faulty solenoid. After replacing it the same continuous clicking is generated. Here is a youtube link around 0.12 in video that sound is more audible. Is this normal? Thanks.