i did a swap for a friend of mine a 92 ls with b16a1 he was using a 95 gsr ecu and everything was perfect, he had it for a while, we went too the bone yard and found a 93 gsr that was wreck from the back so he bought that ecu know we have a check engine light and will not go past 7500 rmp why is that . i think its reading code 21 but there no such thing
Why don’t you just use the 95 GSR ECU instead if everything was perfect then?
i thought that 93 was better than 95
I’m not sure on that. I would think they’d be similar. Anyone here know differences between those two? I’m curious on that too. Fuel curves might be different?
Anyway, for me, I’m using a P28 (92-95 Civic) ECU reprogrammed to DOHC VTEC specs…GS-R specs I believe. What year, I don’t know. It didn’t specify when I bought it.
On the other hand, you can get the V-AFC and set it up how you feel like. 
T
Code 21 is VTEC solenoid. Double check your wiring.
The 92-93 GSR ecu is actually better suited to run your B16A. VTEC X-over for a 94+ GSR is just way too soon at 4400rpm and just doesn’t seem to run a B16A motor as well as a P61.