2008 Prius Breakdown - 4 Codes: P1121 P0420 P0A80 P3012

Hello all,

First post on the forum, but long time Prius owner, had a 2007 prius for several years until an accident and then replaced that one with my current 2008 Prius a couple years ago, it has about 120,000 miles on it and as far as I know the HV battery is original, the cat converter was stolen at one point and replaced.

Has been driving fine then all of the sudden this morning on the way to work the Prius went bonkers and threw these 4 codes along with the red triangle of death.

The HV battery fan turned on in the back, and the prius could barely drive, I'm guessing this was a fail safe mode, I was able to limp it a couple miles back home, but it barely would go over 15 to 20 miles an hour and the accelerator pedal wouldn't do anything which is odd - the vehicle would move forward at 15 to 20 mph with no pressure on the accelerator pedal, fortunately the brake pedal still worked.

These are the codes my matco MD60 OBD scanner read out (this is all I've got at the moment, but sounds like there are better code readers / apps out there that can tell you more info and specifics on the HV battery)

• P1121 - Coolant Flow Control Valve (my reader called it an "Accelerator Pedal Position Sensor problem" but I don't think that description is correct, it should the coolant flow control valve)
• P0420 -Generic Catalyst System Efficiency Below Threshold (Bank 1)
• P0A80 - Generic Replace Hybrid Battery Pack
• P3012 - Battery Block 2 becomes weak

Anyway, I'm wondering how screwed I am here. Did the HV battery and catalytic converter both just decide to catastrophically fail this morning or could it be as easy as the coolant flow control valve have broken and replacing it would fix the other codes because coolant isn't flowing through the system causing all the codes to trigger?

Any input is appreciated.