I'd like to introduce my self, my name is Donald this is my first post hello to all my mid engine Porsche brothers and sisters. I've joined this forum because I'm in need of help trying to make my 1998 986 pass smog in Ca. I know there's been a lot of guys running Subaru power on here. (I found this car half done while looking for a 914 to do a Subaru transplant) it was to cheap and ran and drove so here I am. I'm running a 2000 ej25 sohc adapted to my stock 986 G86/00 5 speed. The Porsche gear box has no neutral switch so I keep getting a P01597 code and then that leads to idle control faults as well. Any help would be very much appreciated.

No wiring diagram for the Subaru?

I would think there are only 2 wires go to the Subaru switch. If so find the wires in the harness and short them together.

Where in the Bay Area are you, I'd like to see that swap one of these days.

It is two wires I have them hooked to the clutch switch so when I engage the clutch kinda like nuetral but this is not working. Thanks for the reply I'm near SFO

It might only want to see the switch closed at or less than a specific rpm. If are over leta say 2K and in neutral it knows something is wrong?

Is the ecu from a manual or automatic? A quick search shows both having them

I have the diagram it works correctly for about a week then the fault returns it's the last fault to fix and I could try to get it smogged. If it was a Subaru you'd replace the clutch switch. Most guys running Subaru power in 914 use the subie trans so they don't have this problem.

I'm not sure if the ecu is auto or manual I thought it was the same the repair manual wiring diagram just shows different color wires in different pin locations for auto and manual. You could be correct about the rpm range could be my switch is to slow ? Or fast ?

Have you ever used one of these, or something similar?

http://www.ebay.com/itm/MEA9161-G-LIMIT-SW...C-/282346461340

It wouldn't take much to fab up a temporary or permanent bracket to make it work like a neutral switch.

I just looked at my wiring diagram again and traced the lines with a highlighter, I missed a splice going to the fuel temp sensor, since I'm running Porsche fuel system I don't have a fuel temp sensor I think its a must be a reference voltage. I like your idea of the neutral switch but would be hard to do with the later two cable shifter system in the 986, but cool switch thanks for your input.

Connect a bogus switch through the clutch pedal switch. Have a relay trigger it when you push in the clutch. ECU should only look for it while starting.

So you think it should only have power while cranking? I have no relay hooked to my clutch switch but have power to that switch with ignition switch on.

Depends upon which Subaru trans. Some use N/O neutral switch some use a N/C switch.

I'm running a Porsche trans. What's n/o and n/c ?

normally open / normally closed

First off, couldn't find that code you referenced.

Second, all modern manual trans cars have a safety feature that requires the clutch pedal in, in order to engage the starter. Keeps drivers from starting the vehicle in gear and crashing into something.
The Boxster should have the switch at the clutch pedal like the subie would.

The neutral switch affects engine power. I normally only see that in auto trans as it's the equivalent of the clutch switch, but located on the shifter.

Auto and Manual ecu's will have different software. The Auto talks to the trans ecu and will throw codes if it can't get the data it wants.

Idle control faults sounds like an Auto ecu. It will kick the idle up when in gear to compensate for the trans load. A manual ecu should solve your problems.