Chipped P05 ECU problem

OK, so I've chipped and converted a P05 to VTEC in preparation for my B16A2 swap. I'm currently running a B20 with a P75 ECU. I've tried loading stock B20, and B18B maps to the chip and attempted to see if it's working. Every time I crank the car I get a CEL and irregular idle (jumps from 500ish to 1000ish). I know it's got something to do with the chipped ECU, because when I connect the P75 ECU the car runs fine. So I guess my question is where should I start troubleshooting to find the problem? Or are there any immediate things that come to mind for anyone that I should be checking?

Thanks in advance!

Edit - I just jumped the service connector and I'm getting a solid CEL.