Ok so it's a Jdm itr the check engine is off at idle and about 2-5 mins into driving it comes on I'm guessing it's the 02 sensor but anyone ever had this happen to them

 

pull the code, come back and post it up.

 

If you wanna make it a guessing game, then throw up some odds and let's get some cash involved. Otherwise, pull the code and let's discuss solutions

 

Code 23 knock sensor

 

Ok so I checked the code it's 23 knock sensor now it's a Jdm itr swap into an ls integra the shop used my ls harness and added vtec wires I just checked under the intake manifold and there is no connector plugged into the knock sensor and the only connector not plugged in is a grey 2 pin connector but my itr knock sensor is 1 pin was the shop sapose to take the knock sensor connector off of the itr wiring harness and add it to my ls harness

 

OK, so the 2-5 minutes thing before it throws a code is most likely how long it takes the car to warm up and then the ecu starts to actually use the engines sensors, when its cold it does not.
It is obviously a motor swap, so are you using an obd1 ecu? if so if its not a gsr or obd1 b16 ecu, the rest of the obd1 ecus do not support a knock sensor. Also, jdm motors do not have a crank fluctuation sensor (cfk) on the motor, any usdm ecu will be looking for this sensor, is it possible u misread the code?