Hello forum members: My 2005 Prius was parked on the street and sat idle for about 5 months (since July, 2022). I have been driving another car of mine since. Before I made the Prius sit idle for 5 months, there was no noise coming from the engine compartment. It was all good. Today, when I started the Prius, there was some loud noise coming from the engine compartment. I couldn't figure out. I have uploaded the video of engine noise to this thread. If you know or have an idea or can make a guess what this engine noise is, please let me know the reason for the engine noise and how I can reduce and/or eliminate the engine noise. Video link ^^^. Thank you in advance for your time and any suggestions and advice that you could provide to me to reduce and/or eliminate the engine noise.
Didn't watch the video, but will guess that one of your illustrious neighbors borrowed your catalytic converter.
Thank you for your reply. That was my first fear and I looked under the car, and I thought my catalytic converter is still there. I could be wrong, as I am not sure. Attached are the pictures. If I need to jack up my Prius and need to look further thoroughly for the catalytic converter, I will do that. If you want me to jack up my Prius and post further pictures, please let me know. Thank you in advance again.
Push down on the top of the air box. That sound is usually an air leak because the snaps have been abused when people change air filters with aftermarket junk that is thinner
Thank you for your reply. Are you referring to the black rectangular plastic thing in the middle? I did push down the black cover on top of that thing, and the noise did not go away. How hard do I need to push down?
And your pictures I cannot tell if the converter is gone If you just reach your hand under there with the camera and your finger on the shutter button and aim your camera up into the forward hole so you want to be arm stuck under the car at about mid-door level and then the camera lens pointing up 20° towards the front of the car that'll show the pipe and the converter if it's there that would make sense for a loud noise like you're talking a loud noise like a loud exhaust pipe correct like what the kid down the street has attached to his mustang or not attached to is the case may be or are you talking aloud engine rattling everything else sounding normal just like a bunch of nuts and bolts bouncing around in the valve cover quite a different noise
The first two images show the long 'resonator', just to the right of that is a catalytic, then another goes up at an angle towards the engine bay. If it sounds like a harley, then the catalytic is gone. Do you have warning lights being displayed on the dash, or OBD2 codes worth posting?
Will look for or try to get the pictures of catalytic converter later when I find time. Went to Autozone and got the codes. P0037 - Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2) C1241 - Low battery positive voltage or abnormally high battery positive voltage. However, it says "good battery" when the battery test is done with a battery tester device. See attached picture. Also, there is a check engine light on the dash. 144 Lumen Ultra-Bright Portable LED Worklight/Flashlight
AutoZone's battery tested devices likely inadequate. It's probably one of those cheap little gizmos that test internal resistance of the battery. Only a load test can be relied upon