2004 Prius 220k miles bad hv battery & cat conv

you can sell the car for more (at least $2000) on craigs list....check out the videos on youtube on how to rebuild the battery...you can find cell's on e bay for about 40 bucks and I have never seen more then two go bad inside the battery pack. so for under $100 and about 3 hours times you can have the car running again..good luck

 

My advise to you is yes keep the car!
first i would just like to give you some information to explain how is HV battery work that way you know that the newer HV battery pack is not necessary to be a good battery specially if it was setting at junk yard !!so please read the following then I have some more answers for your questions regarding the catalytic converter at the end of this important information from our own experience through the years!
**A nickel–metal hydride battery pack Gen2 or Gen3 is a chemical reactions battery that made of 28 nickel–metal hydride/electrochemical battery modules that convert the chemical energy into electrical energy.
so Each battery module contains some chemical materials like the hydrogen and the potassium hydroxide,..These chemicals reacting through some process inside each individual battery module, these chemical reactions process will produce energy, and these energy eventually becomes an electric power within each battery module individually that will add up to produce the minimum enough power that will be translated later to voltages and capacities that can be measured as numbers with the right devices!! so in generation2 or generation3 Prius ,the minimum voltages requirement for the operation to be conducted Normally is 201.6 Dc Voltages by Toyota Standard *and since each battery module made of 6 nickel–metal hydride battery cells that connected in series and have a minimum of 1.2V x6 cells that's a 7.2V ,So each module suppose to Cary a minimum of 7.2v multiply it 7.2 V X 28 (NiMH) modules inside the HV battery pack that's The total voltages of 201.6 DC V " by Toyota standard" ,so these total voltages can supply the minimum enough power needed by any part that needs electricity power supply to perform within your Prius gen2 or Gen3 weather that power is AC or DC power needed by each different part ,then the inverter (electric motor) comes in place to do the work using its own Converter inside the motor case , so it can send a different type of electricity as needed by each part within your gen2 or Gen3 Prius .
That process must happen in a balance ?Same time discharge at the same capacity and same time charge at the same Capacity as well !!! so if you only replace one or few modules then there will be unbalanced charging and discharging process !! that's because you put modules that carry a different capacities !! and that will work for sometime then the strongest modules will survive and the weakest modules will break down suddenly causing a red triangle !! and one or more hybrid battery pack OBD codes !! this is from our own experiences almost 5 years now !! We have upgraded our system with a newer system that imported from out of the states and allows us to get the right numbers and the correct battery balance with the exact capacity that each hybrid battery module needs !!So each individual (NiMH) battery module that we install inside any HV Battery Pack is a completely Re-manufactured (NIMH) module that we bring to a Capacity level that matches the factory battery module from Toyota using our Latest Technology and Newly upgraded computerized battery analyzer and charging system ,also We install a completely rebuilt HIGH VOLTAGE BUS BARS to insure an excellent connections with the HV-(ECU) ,Also we install the Prius Re-manufactured hybrid battery pack in one of our Prius fleet and drive it for a minimum of 50 miles to insure the quality as a final stage so at the end you can get a very reliable, quality and affordable Prius Hybrid battery pack .
For more info please go to Prius Hybrid Battery Rebuild
or contact me at any time if you ever encountered any issues with Toyota Prius Gen2 2004 to 2009 and I will be more than happy to assist you.Now regarding your concerns about the P0420 Catalyst System Efficiency Below Threshold,we have seen several Prius in the past when they gets any of theses hybrid battery OBD Codes codes PoA8o,P3020,P3000 they also sometimes comes with a different codes as well!!
the only way to know is more deep diagnostics to find out about the Catalyst System and if it happens to be a bad then yes you will have to get an OEM used certified catalytic converter and that is the entire muffler since it comes as one unite !! and you can get a very decent one from any gen 2 certified one will cost you about $600 to $900 with the core !hopefully this is not the case!
let me know if you have any more questions I will be happy to help
We are open 24/7 standing by to assist and help !
Joe
Prius Hybrid Battery Rebuild San Antonio TX
Prius Hybrid Battery Rebuild

 

Whaaa!! $750. Don't let Carmax have it at that price. I have plenty of customers/enthusiasts who would buy it tonight at $750!!

I would avoid junkyard packs simply because the quality is unknown. And even with a 30 day warranty, if it fails, you'll have to pay to have the failed one taken out and a new one put in.

Not sure how close to "Chicagoland" you are, but if you are up for a trip to Madison, I could help you out. Or since I do mobile service, I could come to you. And regardless, I'd be happy to chat via phone as well.

A good, independent hybrid repair shop would have a deeper understanding of the hybrid system than most general technicians.

If your car has to be smog checked, then you mat be stuck taking care of the catalytic converter, regardless of whether or not you'd prefer to wait.

Great explanation by Joe. I won't even try to add anything to it.

Anyway, nice that you were able to post the codes so we can better "armchair diagnose things.
Best of luck, you have a challenging decision to make.

 

I never balanced my battery cells after the rebuild and that was 20,000 miles ago...just made sure the replacement cell was at 7.4 volts when installed...as far as a place to work on it rent a storage shed for the month for $70 bucks...its a 3 hour job after you get the cell's order 2 and resell the extra one if you don't need it...

 

Hey GreenCleaner,
I'm not sure what the problem is with Eric not answering but, I can tell you that he has a great and helpful reputation on here.

 

That's odd. Just got new phone service and had problems dialing out. But I have received plenty of calls inbound. I'll have to have it checked our. Thanks for the feedback.

You are on the right path. Keep us updated.

XT1049 ?

 

Regarding the P0420 catalytic converter.

As long as you are not in California you can use this aftermarket cat:
Magnaflow 99205HM Weld on High Flow Catalytic Converter Round 2 25" in Out OBDII | eBay

I have used about 10 of these over the last 2 years and haven't had a problem.

Find a place ahead of time that will weld it on for you. Try small local muffler shops. The cost of this part is $89, you will pay $50-$75 to have it welded on and can scrap the old cat for $25-$50 on craigslist. (there are precious metals in catalytic converters and there is a high scrap value). If you don't have emission testing where you live and don't mind looking at the CEL then let it go. I would invest in a cheap code reader so you know if you have any other codes.

 

I spoke to her on the phone the other day. She is in a smog test area, so that is not an option.