p1508 and p0505 help

[bully426]

So i have a 2000 honda civic recently did a mini me swap idle is very unsteady bouncing from 500-1300 back and forth also after about 5 mins of driving when feathering the throttle around 1500 it stutters. i can force it pass the stuttering but it keeps happening. ok heres what i have done clean IACV performed idle relearn afterwards( didnt work) 2) cleaned throttle body didnt work 3) adjusted idle screw didnt work. Also when car is running and i disconnect TPS no change in idle im thinking tps has gone bad looking for some confirmation before i spend 40 bucks

 

[lethal6]

Well, considering both those codes mean there is a fault in the IAV system that is where you should be focusing. Did you search troubleshooting for these codes? Most of them lead to a bad IAC and worst case it's the ECU. None of them say to clean the IACV (they have to do with faulty shorting inside units or bad wiring not dirt) and none say to mess with the TPS or the idle screw so I don't know what the thought process was with doing those.

0505 is one of the easiest to troubleshoot. Clear the code, unplug the IAC, run the car. If the 0505 comes back it is NOT the IAC and is a fault in the wiring and you then need to find the bad or shorted wires. If the wires are fine, the ECU is bad.

If the code doesn't come back, the IAC is bad....replace it.