Hey guys, I noticed with my TRUCK (04 F150 5.4) that when starting it and its warmed up, when I stop somewhere, as soon as I put my truck into park and sit for a bit, the RPM idle will fluctuate from idle down to almost stalling, but then eventually even itself out (after about 10 seconds). You can hear it in the exhaust when the RPMs drop and about 10 seconds or so a loud tick will like pop and then it resumes normal idle. I heard it might be the IAC but the 2004 - present trucks don't have an IAC anymore, just a TSP. So I was wondering if this is the problem that the TSP (or IAC if applicable) needs to be changed or cleaned? How would I do this?

Thank You-
Casey