98ekb16

Recently I bought a 98 dx from copart that has a jdm gsr swap. Engine has a Skunk2 intake manifold, Edelbrock tb, aftermarket fuel rail, I think the injectors aren't stock but I' not sure, and a Type-R header. It was running on a p2e ecu just to move it around the yard. So far all i have done is swap the ecu to an obd2 p72 and do the CKF trick. Car now starts much better and i don't have the cel staring me in the face with the car off. CEL is on with the car running, I am waiting to get my code reader back from a friend before I can pull the codes. I know that it will show a code for secondary o2 (there is none) and IAB (again there are none), but not sure if there are others.

At the moment the car seems to run fine, but it won't rev past 2500 rpm, feels like a fuel cut. Could this be due to not having IAB's? From what I've read if there is a fuel cut from removing the IAB it is around 4500. Can you run a gsr without the IAB and not be stuck in limp mode? Any idea what would cause a 2500rpm fuel cut? As soon as I get my scanner back I will update with the codes it shows.

Unfortunately I cannot contact the person that built the car so I have no idea what ecu they ran the car on, all i can guess is it was either a JDM p72 or it was running a chipped obd1 ecu, but there was no conversion harness in the car.