Kroon Harness for 944 Turbo

[Mscromer]

I don't trust the F9 log re the idle stabilizer. At least on mine, it seems to read backwards -- i.e., when it says 90% open, it's really 90% closed. I've flagged that before here on CP, and pinged Joe about it, but never got a response. I'll see if I can do a little testing this week to prove or disprove that.

But to your question, if you had a vacuum leak, you would expect the ISV to close more to keep the idle at its commanded rpm...

The map sensor thing with the F9 DME is real and we documented it in detail in the chip tuning guide, but it's a super subtle issue though. On a stock chip, the result is an idle set to 800 rpms rather 840, which makes for slower/weaker idle but otherwise no real issues. Like I said, it went unnoticed to the world, including Joe, until we went on a quest to control idle rpms in the maps and realized this quirk sent the code to a vestigial idle map set to 800.

My car has a little bit bigger cam so that might have compounded the F9 DME quirk, but on my car it was a significant difference. My car idled like total crap until I shorted out the MAP plug.