so ive had this car for 2.5 years now... im in upstate NY, of course and you can't have check engine light on. We've done so much to it, its insane. Current status is trying to do a drive cycle without any codes popping up and the 3 codes to clear. well the latest codes that popped up was IACV and EVAP. There was still air in lines which we got out and now nothing has popped up yet .... cross my fingers lol what other things could all of a sudden make IACV pop up because it never did before... It has new almost everything seriously... I just replaced the speed sensor which was $175 later, it has new O2 sensors, new after market Skunk 2 header, wires, plugs, TPS sensor, radiator, thermostat, stage 3 clutch, stage 3 flywheel, short shifter, new battery, full racing exhaust, drilled n slotted rotors, new timing belt and water pump, distributor, motor mounts, etc. The list goes on n on so... any ideas or suggestions on just getting the damn thing on its way would be helpful.... I just wanna drive my baby THank you in advance

 

What ECU? A GSR ECU may not recognize the Civic EVAP system.

Post the actual OBD2 CEL codes.

 

The ECU is from civic P72

 

the code p0505- Idol Control System Malfunction

 

Is there any idle problem? Does engine idle to spec when warm?

 

yes sometimes it feels like it wants to stall, the rpms fluctuate low to high,
we did replace the TPS sensor and the Speed sensor we replaced just last week.

 

Test the ECT sensor, bleed the cooling system (see service manual for your B18C1), and adjust the idle speed.

Is P0505 gone now?