Looked around and could not find info on 2 codes. 2004 Prius : P0420 and U0293. One I believe is lost communication w/ hybrid system. Are these serious?
I have the codes for the 2010 but not the 2004. I do not know if they are the same or not but will list what I have. DTC CODE DETECTION ITEM TROUBLE AREA MIL MEMORY DTC FOR MEXICO MODELS U0293 Lost Communication with HV ECU - Wire harness - Power management control ECU Comes on DTC stored Applies P0420 Catalyst System Efficiency Below Threshold (Bank 1) - Gas leaks from exhaust system - Air fuel ratio sensor (sensor 1) - Heated oxygen sensor (sensor 2) - Front exhaust pipe assembly (TWC: Front and rear catalyst) - EGR valve assembly Comes on DTC stored Applies I hope this helps.
Lacking a complete manual, if you plug your trouble codes into Google you can usually do OK. I got some hits for your generation Prius on Google.
