Subaru gurus i call upon your knowledge, i need to know what sensors i need. For instance what do i do about the downstream o2 sensor since i dont have a cat or what is necessary to either run a vss? Anything like this is helpful as i want to make sure i have it tight before i go further. Thanks all!

the bible i am using for my 1990 ej22.
you need to tell us if you are planning to use stock ecu, i'm assuming you are.
http://www.shoptalkforums.com/viewtopic.php?t=136053

Also depends on what year Subaru you're using.

On my 96 2.2...

Down stream O2 sensor not needed. Will throw a code but won't affect how it runs.

If you use the subaru transmission it will have the VSS unless it's a 1996 or older if it is or if you are using the porsche transmission then you will have to make one or buy a kit to install one on the CV axle.

im using stock ecu ej205 and Subaru trans

On my eg33 (svx), I keep the O2 sensors.

I assume u don't have a cat, does it weird it out at all

I haven't ran the car yet but the tech that worked my ecu harness said I needed to keep the O2 sensors. He's done a lot of harnesses. I'll defer to his experience.

Correct, no cat.

The eg33 is a vintage that doesnt have a post cat sensor, my ez30 throws a code for not having the post cat sensor and a few others, but hasnt effected drivability. Safe bet is keep any sensor on the engine harness, VSS, and pre-cat o2 sensors. The ecu may also need to see a signal/short from the transmission/neutral safety switch.

Vss can double as speedometer signal using something like speedo healer to convert the pulses (I.e. to an electronic 911 speedometer)

The rear CAT is used only for emission reports so not necessary in your case. The VSS should be re-connected to the ECU. It will run w/o it but it will stall momentarily every 6 min's when on the hi way.

that sounds like it sucks maybe u should get that checked out lol