Hey guys,
i got a 99gs-r in a 96dx ek. i did the swap with 96 civic ex harness and wired up all additional sensors and wires. running the 99 gs-r ecu also. problem is that when i drive the car around it will idle a little rough like it has a slight misfire problem. when it runs like this the CEL starts flashing. i checked the codes the other day when it was running really bad and these codes came up:
22-Vtec System Malfunction
45-System too Rich/Lean
71 through 74- random misfires
the car only runs like sh*t when it idles. but once the car gets rolling it runs fine. it is only when you come to a stop that it runs like crap. help me out guys. ever seen anything like this? its starting to **** me off that its running so crappy at idle.

 

Well your code 22 is your VTEC pressure switch. Make sure the harness is plugged in and the correct wires are hooked up for your swapped engine. If they are correct, you MAY need to replace this. Anyway, this wouldn't affect your idle, just your VTEC activation based on RPM.

These are things that may affect idle, TPS sensor, Idle Air Control Valve, Throttle Body set screw, Fast Idle Thermo Valve just to name a few.

You might want to start here.