as i changed my ecu i noticed a small little black box with a red led light embedded in it. can you tell me what the hell is that?

i did a motor swap and changed to a fully built b18a nonvtec. so i ran it with the stock itr ecu and there was a lot of black smoke and all the sensors was going crazy. after changing to an obd1 ecu there was still black smoke but the sensors were ok except for the air sensor. so we unplugged the little black box then then ran it, then there was a little light gray smoke. i don't know what i hell i just unplugged but i hope that it didn't hurt anything. please help!

 

Ummmm you took out b18c5 for a b18a, not even a b18b; but a b18a. Whoaa you're blowing my mind, is there something I missed..
OK OK enough sh*t talking, we need to know what harness you are using what type of obd ecu you are using and how you modified a few things, ie: fuel sending unit to recognize non vtec and so forth..

 

well, first its a fully built motor that does 12s. the type of harness i'm using is obd2.1. so what i did was buy an adapter that would connect the obd2.1 to a obd1 so thus i could use an obd1 computer. but still, that little black box was there, what the hell is that?

 

Alarm?