what is the difference between the different series of obd, and also what series came on which year preludes?i just want to know.

 

On Honda Preludes...
Pre 1992 - I don't know
1992-1995 - OBD1 - Basically just used by techs as a diagnostic tool. Does not really do too much emissions-wise. Does not hinder performance very much if at all.
1996-1999 - OBD2 - secondary O2 sensor added. Compared to OBD1, the ECU is far more aggressive at retarding timing when emmissions exceed standards. This generally reduces effectiveness of bolt-on upgrades.
2000-2002+ - OBD2ver2 - Some people make this distinction for cars 2000 and later. I don't know what the difference in performace or functionality vs. "OBD2".

Andrew

 

thanks for the info.
is there any way to switch from obd2 ver. 2 to obd 1?
will i just have to have the computer and harness?

 

It's not that easy... On a 97+ Prelude, to switch to OBD1, you need:
1993-95 P13 ECU
OBD2->OBD1 wiring harness adapter
OBD1 h23 or h22a distributor with all sensors
Modify the distributor wiring harness for OBD1 distributor

AND either one of the following:
1993-1996 H22a peak and hold type fuel injectors
OR
"Resistor pack" from the fuel injector wiring harness from a 1992-1996 Prelude or certain Accord models (not sure which Accord...)

Andrew