Originally posted by dantastic
u need to mod ur ecu inorder to hook up hondata to it. the only obd ecu u can flash is the rsx. im 99% u cant flash anything else yet. thats why ppl run obd2->1 jumpers to run hondata obd1 ecus in obd2 cars
You're right a Hondata ECU must be first moded in order to flash it since they are OBD-1 setups.
As for the Honda ECU's that can be configured via the diagnostic connector. Any OBD-2b (RSX and other late model Honda's) and probably (all though I can't be certain) OBD-2 Honda ECU can be tuned without the need to "chip"
The reason people convert OBD-2 to OBD-1 is simple really. Cost. Cost drives everything. OBD-2 ECU's have there processor/micro controller and eeprom incorperated together and is quite expensive to pull and program. Each one of those chips cost about $200. When an OBD-1 eprom (TI27C256) can run you as little as $1 each and can be swaped all day long.
The OBD-2b and OBD-2 run an eeprom instead of eprom which means the eeprom is electronicly erasble which is how they can be programed via the service conector. Although already done the software/hardware to do this is extremely expensive now and in reality if you don't own a shop or are a large tuner that deals with this on a large basis it's just not worth the investment. So they just convert OBD-2 to OBD-1.
I prefer OBD-1 simply because I know more about it and I can program it but OBD-2 systems are pretty bad ass in how they can help technicans find and repair problems.