I recently borrowed an engine code scanner after my check engine light went on and got a P0505 code on my 2004 Prius with 185,000 miles and started to fix things. I replaced the PCV and spark plugs as well as the air filter. It ran fine, but decided to also clean the MAF using CRC MAF cleaner and also clean the throttle body and butterfly using CRC Throttle Body cleaner. I also carefully washed out the engine compartment using Gunk Foamy. I seem to have put it all back together, but now the ICE won't shut down, even when warm, and actually wants to rev beyond what seems to be needed. I got another scanner and got some stuff that I honestly don't understand. It said 2 codes then gave me P0505 followed by: Mil On Monitor 0 inc 6 ready misfire fuel comp catalyst evap O2 sensor This is starting to get scary can someone suggest a cause and solution?
I had the traction control light come on and couldn't drive over 35 once when I cleaned my very dirty MAF. Disconnecting the 12 volt system for 10 - 20 secs and reconnecting cleared my problem, this may do the same for you, as part of your problems appeared with the cleaning. Looking up P0505 points to a problem with the electronic throttle motor, so if this code comes back, I would consider replacing this. They rarely go bad, I would consider used for the replacement , research more on this, I haven't personally dealt with it. Diagnostics for P0505 Google Drive Viewer
