Wander Idle
 

1998 Boxster 150,000 miles.

The idle when warming up will wander from 500 to 1200 RPMs. After about 5 cycles, it settles in at around 900 RPM.
Just took my first drive in the car and when it warmed up, the idle wanders when coming to a stop.
At one stop it died.
It does not idle rough, just wanders.
No codes appeared.

I have replaced the plugs, coils, oil and filter.

I need some help on where to looking to solve the idle issues. Thanks!

How do your fuel trims look like, are they far from normal?
I would start by checking and cleaning the MAF if fuel trims are negative.
Or checking for vacuum leaks if the fuel trims are positive.

What tool do I need to check the fuel trims?

I do have a scanner if that is the tool to read the trims.

Cleaned the TB, MAF sensor and IAC. One of those fixed the problem.