I have a 99 Si w/ a reprogrammed P28. Connected the Field's last night to the harness, soldered all connections, hooked it up as an OBD I ECU.
Started fine, VTEC control works, speedometer works, halfway through the drive, CEL comes on. I haven't had a chance to read the code, since it resets after turning car off and then back on, all connections are solid.
Ran car up and down rev range a few times, engaging VTEC. Anyone have an idea??

 

this is typical. how did you hook up the map sensor connections? i hope you solderd it cause if its just twisted together with electrical tape around it, it will act up on you after a couple of minutes of driving. i suggest you solder all of the connections. in the mean time, if the light goes on again while driving, put your key in the acc position for a second and switch it back to on. don't turn it all the way like you are starting your car just flick it on on.

 

All of the connections were soldered. When there were two wires from the SFC to be connected to one wire on the ECU harness, the 2 wires from the SFC were twisted together, then soldered together. Then a layer of solder was applied to ECU harness, then the SFC leads were soldered onto the ECU harness.

 

TTT