So before my rear end and cooling problems started (both now fixed) a few months ago my engine developed a slightly high idle in park. Normally in park it would first idle at 1000 then quickly drop to 800 or so remain there until I put it in R or OD where it's idle is 600-700.
Now it goes up to 1000 and stays there. It hovers been 1000-1200. The engine sounds a little louder too.
Things I have replaced:
EGR (2 years ago. ACDelco unit)
CTS (less than a year ACDelco Unit)
IAC Valve (Less than a year. ACDelco Unit. Did Relearn process)
Vaccuum lines (2 years ago. Made in USA rubber lines. I replaced every line)
PCV (Less than a year ago. Duralast unit)
MAF (3 years ago. NAPA remain).

Could my Duralast PCV have gone bad? Last time it went bad the idle did go up to 1,000 in park but I smelled oil and had a ring of oil around the PCV. It was the original AC Spark Plugs unit I replaced.

I'll try either replacing the PCV again since they are cheap and try the crab cleaner trick for a vacuum leak. Any other suggestions? It seems like once every few months to a year this high idle in park problem occurs again.

 

Did you ever find out what it was? If it’s idling high Re-check the timing set on the distributor, it may need to be re-adjusted.

 

I didn't because then I started having all those electrical issues. I'm leaning towards it either being timing or the TPS is bad. The TPS is the only thing on the TPI that I haven't had to replace.