p0420 code can it trigger code p3125

DTC P3125 means that the inverter is not working properly. This has nothing to do with the catalytic converter.

As you probably know, the catalytic converter has an HCAC (hydrocarbon absorption chamber) which is unique to Classic Prius. I don't know how you are going to get an aftermarket product for only $300 unless the HCAC comes from a salvage vehicle.

Considering your high odometer reading, it is possible that the inverter has failed. It is also possible that the inverter coolant pump is not running which caused the inverter to overheat. If the pump is working you may be able to hear it (near the driver's side headlamp) and you should see turbulence in the inverter coolant reservoir. You should also note the fluid level is higher in front of the reservoir as compared to the fluid level elsewhere in the reservoir.

 

Are you planning to buy a salvage inverter? Looks like the going price starts at ~$300.
01 02 03 Prius DC Inverter Converter G920047070 OEM LKQ : eBay Motors (item 190364176193 end time Feb-09-10 10:56:52 PST)

However, I recommend that you note the part number on your current inverter, and purchase one that has the same part number or greater (i.e., the same or a newer revision.)

 

I'm in Huntsville AL, 3.5 hours away. And I make 'house calls.'

Lets touch base again on Friday. Depending upon weather and my wife's health, I could be there mid-morning Saturday ... with the dog and tools.

Bob Wilson

 

The important number is the part number, which is G9200-47070 on the unit for sale. That inverter is from a 2001.

If your current inverter has a part number suffix greater than 47070, I would recommend you pass on buying this particular unit.

 

One last thought: your OP dates back to May 2009. If your car's just been sitting around idle for 8-9 months, there is a reasonable probability that the traction battery is dead by now.

 

If the main battery icon appears on the MFD, that is evidence that the traction battery ECU has logged a DTC.

The traction battery SOC gauge reading of 25% is also not good as the Classic SOC gauge normally will read either 50% or 75%.

Once you get the inverter working again, maybe it will restore the traction battery. However, be advised that you may also need to replace that battery.

 

Well if you're looking for a "Certified Technician," I'm not qualified. No doubt the other "Certified Technicans" posting here will continue to help.

I'll pass and stay in Huntsville with my spare inverter, two volumes of Toyota Maintenance manuals, Electrical Wiring Diagram, Graham scanner, test instruments, tools, and five years of self-maintenance. You win, I'll stay home:


Bob Wilson

 

Well, I've had p0420 off and on for about 2 years now, with no apparent reduction in performance. However, wife is angry at living with CEL nearly always on, so will repair/replace cat this spring.

By the by, Bob, when my 2003 developes some critical problems, I'll ask to bring it down to Huntsville if I have to carry it on my back. You're "certified" enough for me.

 

Failure of the catalytic converter will not impact vehicle driveability or performance. The main concern is that the car is emitting more air pollution than necessary.

 

Sounds like a plan. If I can find an excuse to head up Nawth again, I'll try to visit. I'll bring my own grits and Dr. Pepper. <grins>

Bob Wilson

 

OP may have just been asking, and not meaning to imply that you aren't skilled or qualified...

 

What steps would you have taken to diagnose the inverter?