Will these two conflict on my 1997 base prelude. I know that obd 2 likes to reset and get the best for stock engine but what if i get a harness to plug into the ecu? I looked for this but there was only something for a gsr i found 04 or something like that.

 

The A'PEXi SAFC, VAFC, and AFC-Neo are not really specific to any vehicle. In other words, it doesn't matter if you have a Prelude, a Civic, or a GSR, the same device is used. Also, OBD2 should play no part in it. The main purpose of these piggybacks is to trick the ECU into using specific A/F ratios. The VAFC is better than the SAFC for a couple of reasons. First, VAFC allows for the adjustment of VTEC engagement point. Second, VAFC allows for 12 adjustable points in increments of 100RPMs. The SAFC also allows for 12 adjustable points, but only in increments of 200RPMs. The AFC-Neo allows for 16 adjustable points, but doesn't specify the increment. Also the Neo allows for the adjustment of VTEC engagement. I definitely recommend doing more research on this. Try their website:

http://www.apexi-usa.com/product_electronics.asp