P0505 OBD Trouble Code P0505 - Generic Type Powertrain - Vehicle Speed, Idle Control, and Auxiliary Inputs - ISO/SAE Controlled Description Idle Air Control System So my car hit this error code. I've had some missfires but now it's just misfiring on cold start up. It has done 280,000 miles, uses about a litre of oil every 3000 miles. Under the bonnet (hood) it does have a hissing sound but I can't locate the leak. I have changed the pvc valve and reattached the hoses. I haven't yet installed my oil catch can yet and I've also got the P0420 bad cat code. How do I find an air leak? I've cleared the code and disconnected the battery as I also replaced the fuel injectors. I've since had my orginals reconditioned. MAF has been replaced with a known good 2nd hand toyota part. On the plus side the car constantly runs the ICE so I've finally been able to bleed the radiator fully and I have warm (not hot) air blowing. This may be another option for bleeding the radiator, introduce an air leak. If it's post maf air leak I'm assuming hoses on the throttle body but they look good. Anywhere else likely?
Somebody has posted the workup pages for that code. The fortune cookie for that one is a little misleading, as the Prius doesn't really have what other cars have called an "idle air control system" adjacent to the throttle. It just has whole throttle operating under computer control. But that kinda sorta has the same responsibility for controlling idle speed, so they reused the code.
