I just had the vacuum pump replaced on my 2018 Tacoma for the same reason. No difference on the ticking sound. I was not able to talk to the mechanic but I asked what the vacuum pump pn. 20300-0P040 is for and the service tech said it was for emissions but research said it was for brake system...
Just had my vacuum pump replaced on my 2018 Tacoma. No difference in the sound. I was not able to talk to the mechanic but the service rep said it was a emissions vacuum pump they replaced. I don't think that was correct. From what I read it is a brake vacuum pump. I can't find the installation...