Cel P0446:anyone please help!!!

[stund41]

Hey guys,

Figured I would have to post this because I am all out of cures for the problem. Check engine light came on in my 01 solara (v6 supercharged),
Engine code P0446: Emissions control malfunction.

sigh....here we go,

Took the car to toyota because even though I had the code and the description, I personally know that there are a number of factors that can be involved with this code, and therefore a number of cures as well. (hence this website.) They automatically charged me $90 for the diagnostic even though I had already told them the code (that kinda sucked.) When they evaluated the situation, they had told me there was two problems.

A. One of the temp hoses was kinked and therefore not getting any air through. (which if I understood correctly, had something to do with my injen intake: with CAE) and therefore to solve the problem, was rerouted (so I am told)

B. Fortunantly, the code falls under the emissions warranty on the car, and because of this, tomorrow I am taking it in to get a brand new computer put in to cure the emissions problem (again I am told over $2000 worth of combined labor and parts.) all on toyota, not a penny out of pocket. which is a relief.

okay; here is the thing I need from my fellow soloraguy's:

1). can anyone direct me to any of the temp hoses in the engine bay so I can look to see if anything was rerouted or changed: because I honestly don't think they touched anything and instead just cleared the code.

2.) Ever since the light was on I feel as though I had lost a nice amount of power from the supercharger. To give you an idea, the people with the Injen CAE on their superchargers; we all know that the sound of the whine is overwhelmingly loud with the blower, however now when I floor it (with the cel off) I do get some of the whine, but the oveerwhelmingly loud sound is now the actual engine. (basically more of a grunt sound then a whine.) I fear as though something is loose (the filter and the extension piping, or any of the hoses (which I checked and even replaced one due to a slight tear.)

Basically guy's what the hell is going on?? anyone have the same problem before and even more importantly, were you given the same cure (new computer) any ideas on the grunting sound?? (from the lower driverside fender: CAE) Will this computer thing fix my serious lag and power loss??

I know this is long, but This is a long problem, as always any help from you guys is always appreciated!!!!

Thanks,

Travis

[Sentinel]

Whenever your CEL comes on, the engine goes into Safe Mode. I think that part of this resets the ignition advance to minimum, which causes power loss, especially on boosted engines. Performance should return now the CEL is off.

PO446: EVAP system - vent control malfunction. Possible problems:
Open or short in VSV circuit for EVAP
VSV for EVAP
Open or short in vapor pressure sensor circuit
Vapor pressure sensor malfunction
Open or short in VSV circuit for vapor pressure sensor
Malfunction in VSV for vapor pressure circuit
Vacuum hose blocked, damaged or disconnected. <<<<<< Your problem?
Charcoal canister malfunction

[DaveMush]

9 times out of 10... that is not going to be fixed by replacing the ECU.
You probobly need a new charcoal canister. That is a REALLY common code these days because people dont stop putting fuel in the tank when the pump clicks off.
Adding a lil' bit more fuel, and a lil' more to round it to a nice round dollar at the pump is actually forcing the charcoal canister to fill with gas... Making it a big tank of crap that cant do its job.
The canister is mounted up under the rear cross member and has (2) of the VSV's attached to it. Basically they all go bad due to constant liquid (not vapor) gas in the canister.

Cost of a new canister unit w/ sensors ~ 400

[ozone]

I had the same code in my wife's car. I do all my own work and consulted the big books, following the diagnosis procedure.

I doubt very seriously that it's the ECU. It is rare for them to go out unless you know you zapped it or something.

The first thing that should be changed is the gas cap. It's a simple repair, but when it malfunctions can trigger the PO446 code. After that, the two VSV's should be checked. There is one on the charcoal cannister, under the rear suspension member and one on the engine. Then all the vacuum paths in the charcoal canister should be checked. This is where my wife's failed. The charcoal canister would not hold a vacuum.

Although overfilling the gas tank can mess up the charcoal canister, no doubt, I kind of think that they are just poorly built on these cars. If you do enough searching regarding common repairs on these cars, you will find this is a common one. Mine was $292.00 total. I dynoed before and after and the power went up a little after the repair and it smoothed out.

I'm not certain, but I don't believe the ECU goes into limp home mode with just any CEL.

Anyway, I know this thread is old, but I though I would post for posterity's sake.

[PDX SuperSolara]

To those of you with 2001 era Solara, the computers (ECU) in these cars are known to have various emission related problems and they have a extended warranty from Toyota to 8 years 80K miles. The latest problem I have seen occur with this computer is it failing to shift the automatic transmission. This is covered under warranty as well. But the P0446 MIL especially has a TSB.

[Ruski]

i have the same codes on my 00 solara P0446 P0441 P0440 all these three codes result in the charcoal canister. i dont believe changing ecu will solve this

[Fletch]

The engine doesn't go into safe mode with any CEL. I drove for over a year with the downstream O2 sensor as a current code because I was running cat delete, no safe mode, no loss of power.

Of course the knock sensor code is one that puts you in safe mode.

[PDX SuperSolara]

The reason the ECU's are being recalled is because they are indicating a FALSE code, in other words, the fault doesn't actually exsist or the ECU is overly sensitive and sets a code when it should not. So Toyota is replacing them under warranty if yours has the problem. In geberal, Toyota has had a lot of problems with the first gen Solara ECU and that is why they are replacing them for various faults. For instance, some of the automatic ECUs fail to operated the shift solinoids in the transmission so the trans stays in low gear or won't shift properly. This is covered under the extended warranty, even though no codes are set.