2000 Boxster intermittent stall issue

[thstone]

Assuming that the CEL isn't on and there are no codes pending, I'd start with checking the throttle position sensor and the fuel pressure.

[jvfante]

I've chased this intermittent stall or hesitation issue on my '98 2.5L MT 138k Boxster for several months and replaced all the usual items myself: plugs, coils, MAF, O2 sensors, fuel filter, cleaned Throttle body & checked fuel pressure. The car ran great, but still had the occasional hiccups when accelerating.

In desperation, I took the car to a local indie shop and then to the Santa Barbara P- dealer and neither of them (and their fancy machines) could figure it out. They did take my money though and wanted another 4 hours to check my wiring....

Then, thanks to a suggestion to check for vacuum leaks from "itsnotanova" (via his Plano, TX Porsche dealer), I found the culprit to be a slight leak at the coupling between the top breather hose and the AOS. I fixed the leak and the hesitation is no more.

Many thanks to Woody & the guys in Plano.