First off can it be done?
Second, what wiring harness to use and what else to look for.

I read a couple of posts as to what is needed to tune a 93 but, it seems to me it is a hassle to keep removing the chip to program it.

Scott

 

The key differences are the sequential (94+) vs. batch fire (93) injectors, the presence of a mass air sensor (94+) and the electronic 4L60E control (94+).

You need a harness with provision for 8 individual injector signals (your 93 just has one wire for left bank and one wire for right), and the MAF sensor - of course you also need to get the sensor. If you have a 4L60 (93) you need to either delete the A4 control functions, or install simulators to make the PCM think its a 4L60E.

If your 93 is a T56, the new (94+) harness will need the resistor to eliminate the skip shift code.

You will also have to change the O2 sensors.... the 93 uses a single wire (to the ECM) sensor, with no heaters. 94+ uses a 4-wire sensor, with 2 wires to the PCM and two for the heaters.

There may also be an issue with the pulse rate out of the VSS.

You would be best off with a 94 or 95 harness, since a 96+ harness would have a ton of extraneous connections for OBD-II detection devices that don't exist on the earlier models.

 

What issue do you thing I'd run into. Maybe replace the sensor with a 94?

Thanks Fred

Scott