Howdy to all! Long time lurker, first time poster. Appreciate greatly all the knowledge I've gleaned from these forums over the last few years. TL;DR - have a Gen 1 Prius that's been sitting for about a year. P0420 code, dead 12v battery, possible bad traction battery. Do I A) diagnose and fix, B) sell as is, or C) part it out? Story time. My wife's 2003 Prius has been sitting for about a year. The damn thing was running fine, still making about 42MPG in mixed city/highway driving, with about 169,000 miles on the clock. A recurring P0420 code, previously something fixed with fervent prayers and Techron fuel injector cleaner, became a permanent feature. In Houston, an emissions code means the car won't pass inspection, and so the car sat waiting for me to diagnose. The wife and I working 80 hours a week at the time, the car continued to sit. Wife gets a nice bonus, we buy another car, I resolve to diagnose the P0420 issue and sell the Prius for what its worth. Fast forward 15 or 16 months. Predictably, I haven't devoted the time to fix the Prius, or to periodically start it up and charge the traction battery. About eight months ago, I jumped it and ran the car for about an hour. No problem. About two months ago, I finally clear some time to play detective and figure this crap out. 12V battery is dead, so I jump it. Letting it run for a few minutes, all seems well, so I take it for a spin. 10 minutes of street driving goes by, I pass a highway onramp, figure why not? Running around at highway speeds for about five minutes, and I'm thinking all's well - heck, I'm even showing 44MPG on the center display! Reality reminds me that Lady Luck gets a vote when the dreaded PS / MAIN / car exclamation image pops up on the center display, and about 30 seconds after that I'm coasting to a stop on the highway service road. A friend comes to jump me, the Prius comes right up with no warning lights, and I make it back to the house on city streets in about 10 minutes of stop-and-go lights with no further incident. As a minimal diagnosis, I'm planning to replace the Prius' 12v battery with a spare 12v deep cycle that I know is charged and healthy. With that installed, I'll start the car and cautiously run it until I see check engine lights, hybrid warning lights, etc. Any suggestions on diagnosing if the traction battery is bad would be helpful (researching methods now). If the traction battery is good, I'll try selling it locally with full disclosure (anybody interested in a Mechanic's Special? lol.) If the traction battery is bad, I'm not sure what to do. I'm not in a financial position to buy a replacement battery, so I'd either sell it as is or try parting it out. Not sure how much I'd be getting either way - any ideas? Thanks for any input!
Ah, the old "there are diagnostic trouble codes stored to tell you what's wrong with your car" light. You should read those. That will give you the best start on finding out what's up. -Chap
