Just picked up a 2000 civic ex, It keeps throwing the CEL for po505. I searched the forum and thought it was the IAC valve. I cleaned it and replaced the Gasket for throttle body and im still having the same problem when warmed up the idle jumps between 1400-1800 when in park. Any ideas as to what else will cause this problem??? Thanks in advance

 

IACV itself is probably bad... I would try replacing it and see if that gets rid of it3

po505=IAC malfunction

 

Ill prolly go pick one up at the junk yard in the next day, what do think a fair price is for one??? Thanks

 

P0505 indicates either an IACV problem or a vacuum/intake air leak. If you pull off the air intake and use your finger to cover the port leading to the IACV in the throttle body, does the idle speed return to normal? If not, you definitely have a vacuum or intake air leak. Start by looking carefully for a disconnected vacuum hose. Otherwise the throttle body or IM gasket is leaking. Are they torqued to spec?

 

Yea, when i cover the hole leading to the IACV the idle returns to normal. Thanks for your guys help.. Ill pick one up at the junkyard and let you guys know how it goes.