986 Boxster S speratic idle issue

[GungaNewf709]

Hello all.

My mint condition 2000 Boxster S is having speratic idle issues, every now and the it seems to idle wonky, its really slight, but as we all know, generally only the primary driver can pick up on such nuances.
Sometimes when coming to a stop, it can dip up and down by a couple of marks, then equalize. And other times you can feel it when starting to accelerate.
Any ideas or suggestions as to where I can start to look. The coils " look ok"
Any fuel additive recommended?

Puzzled!! Thanks in advance

[mikefocke]

So lets start with it is a 24ish year old car at best.

Maintenance history?
Porsche specific diagnostic tools available (PIWIS, PST2, Durametric, ?)?
Last time the intake and throttle body were cleaned and how?
How old are the MAF and O2 sensors?
Looked at the condition of the plugs?
Ever used injector cleaner?
How old is the fuel? Octane high enough?
Are all the hoses good?
AOS age?

Just random thoughts...

[Danimal]

Also, is it a manual or tiptronic? Many possibilities as Mike noted.