P0446 and Techstream "TBP" Fail

It seems you have access to Techstream running on a laptop, which is the successor device to the handheld tester - for your future reference.

It also seems you are having trouble accessing the potential failed parts, so I guess it doesn’t matter with this particular problem.

 

That is not a good graph. The reference lines are good but the middle graph line that looks like a shark tooth point should be below the two lower flat spots on the graph. The reference is the .020" leak orifice inside the canister. It references the orifice twice to get the baseline and double check the base line.

 

I've been living with the recurring P0446 for a while now. I noticed that after replacing my dying 12V battery the code stopped showing up for a long time. It finally did show up after a few months rather than a few days as before I replaced the 12V battery. When it showed up I put the now almost new 12V battery on a trickle charger overnight and again, the P0446 did not re-appear for a relatively long time. Now I am beginning to get it again. Will try the trickle charger trick again and see. The trickle charge trick may be masking the real problem, but I am really in no mood to go replace parts that really only make the government happy and do not effect the everyday performance of the car. So I just clear the code and go on with life. If the trickle charger trick works for me again I will let you know. My theory is the purge valve is failing and anything but a very strong 12V battery at good charge does not provide enough juice for the test that the car seems to perform when it's parked at night. It's a theory, not a piece of knowledge. I just observed a pattern with the 12V being weak and P0446 re-appearing.

 

I hear you. My 12V experiments may be total coincidence. I have no idea how the test works. Thanks for enlightening me. I think it's a bit of a BS thing to test for and therefore just do not care much if it fails. I think I loose more vapor to atmosphere every time I fuel up at the gas station than anything escaping my gas tank. Some EPA requirements are a bit ridiculous. Especially for a vehicle that produces a small fraction of emissions that say an Econoline van is allowed to produce.

 

With reference to the OP removing hard to get to parts. I have been stared down by jobs like yours and then come back to them a different day I am able to complete the task with a new attitude. In other words good luck.

 

i don't think i've ever seen this before, thanks!

 

I am really hoping I can pass my state inspection at the end of this month by just clearing the code. If I have to go through this nonsense and expense to replace a non-essential part I may be very upset. how much does a new part cost at the dealer?

 

Thank you for the info. You said you fixed it for $600 and I thought that was a bit steep. Now you are saying it can be done for much less. Did I miss something?

Also, this is going to be my second inspection. I bought the car last July and had to do an inspection within 7 days of registration. It passed just fine, but there was no code displayed at the time. The PO may have cleared it or, more unlikely, it wasn't a problem yet. I got the code soon after I bought the car and it kept coming back ever since. I do clear it with Torque Pro app, but it comes right back. I will attempt to pass inspection soon and if the car fails I will need to start looking into it. Other than that I will just live with it. In my opinion, it is a completely pointless code that does not effect anything, including, as intended, the environment. This is one of those mandated BS requirements that was met by manufacturers happy to collect $$ for bogus, but very expensive "repairs".

 

It killed my battery slowly. Died on the road. Now I cant even pump gas without turning the pump nozzle upside down. My code was on for about 7 months.

 

Can you please explain why you think the P0446 code killed your (12v?) battery and why you can't pump gas without turning the nozzle upside down? Your statements do not seem to follow from one another. Do you think the code caused your battery to die? And is making you have to turn the nozzle upside down? I am confused.

I am still getting the code. Had to clear it to pass inspection and then it came right back. I am also having trouble getting the pump to pump more than a few gallons at a time, but that's due to the bladder being what it is and I do not believe it has anything to do with the code (but I may be wrong).

 

1) Part lasted 2018-2007= 11 years
2a) Amortized cost (year): $600/11years = $54.55/year
2b) Amortized cost (month): $54.55/12 = $4.55/month (cost of a grande/venti latte)
2c) Amortized cost (mile): $600/your odomoter reading = $cost/mile

Compare that cost against tires, that you replace how many times over the course of vehicle ownership?
Sure would be nice if all the tires purchased only cost $54.55/year or $4.55/month or $.00001/mile.

Let's put the conspiracy theory to rest.

Manufactures don't want to add to their vehicle costs w/ unnecessary parts. If they could, they probably would not have that part. Remember, post #16 says a new part is $300 retail/online; Lets just say this part costs Toyota $25. Now if this part was optional, every Prius would be $25 MORE PROFITABLE.

If the sales of Prius for the Gen2 years are correct from Carsalesbase, then 748,646 Gen2 Prius were sold.

748,646 x $25 = $18,716,150 lost revenue for an optional/unnecessary part.
Now ask yourself, would a publicly traded company that has to answer to share holders choose an optional part, foresaking $18.7MM in additional profit? If this was your private company, would you choose an optional part at the expense of $18.7MM in profit?

I don't have the sophisticated testing equipment to measure vehicle emissions to see how much of an impact (big or small) this part has. But, the engineers and BIG BUDGET research and development department, driven by Science and facts, not alternative facts, led Toyota to add this part, costing the company $18.7MM in additional profit.

Remember, companies want to maximize profit and always fight/lobby for no regulation or looser regulation that is to their benefit and profit.