matts6887

Earlier today; as i was driving home; the cel popped on and i was like oh !@#$; great; just what i dont need!. So; i went back out and went over to (and i know some people dont think very highly of this place) went to pep boys because that is the closest place to me that will read codes for free. The code that came up was 0446. Which; according to their database; points to something in the emissions system. Does anyone know more specifically what part of the system could be at fault here? From what i was told; it could be anything from faulty wiring to a bad evap sensor and/or charcoal canister. What can you guys make out of this? And while I know its not like detrimental to driving the vehicle at the moment; I think it needs to be resolved as I dont like having that light on as it means something is not right.

carguy07

I think a loose gas cap can set that one off. I would start my making sure it's tight and the gasket looks in tact, reset it and see if it comes back.

matts6887

it definitely cant be a loose gas cap because I ALWAYS and i mean always check to make sure its turned until it clicks after getting gas at which point I know its secure. Im just wondering how much this is gonna run to fix. I figured this would happen to me eventually; fortunately though; it happened well after I had to get my emissions test done in order to renew my vehicle tab and registration.

maxSteel

Check out the diagnostics procedures in this thread
https://www.clublexus.com/forums/rx-...-po-446-a.html

In my case I followed the diagnostics and the charcoal canister was bad.

salimshah

What about the second half of Carguy07's question ,,,, condition of the gasket? Other clues that can help would be, when did you fill the gas last time? Any one messed with thin hoses in the engine bay or back near the gas tank?

The cost will be diagnosis and parts. We can not guess till at least the diagnosis is done. Growing up once my dad paid equivalent of 5 cents for part and $25 for diagnosis. [current times 20 cents and $400]. Problem was a pin hole in a hose that keep sucking in air and prevented diesel pump from compressing diesel fuel to the needed pressure.

ps: If folks dont think highly of a shop it would go out of business. Then there are good and bad every where.

Salim

JAB

Look for a thread begun by 'gomeybear' a few months ago and to which I contributed several thoughts on the subject.

fastnoypi

did you mess with your air filter prior to the code?

matts6887

nope. Havent touched the air filter yet as Ive had no need to.

matts6887

nope salim; no one has done any work with the hoses. I just got gas the the other day but again made sure to check that the gas cap was on securely. I doubt at this point it is the gasket in the cap because if it was this code would have probably popped up a long time ago I would think(granted Im no expert but thats just what im thinking at this point).

JAB

Open up the vacuum canister assembly and I predict you will find either a clogged or defective VSV, and/or rotten vacuum hoses.

fastnoypi

clear the code..if it comes back, bring it to your shop to have it smoke tested and diagnosed. We're just playing the guessing game here.

matts6887

smoke tested? what the heck is that?

fastnoypi

A pretty good system to detect leaks.

salimshah

Since you can not see a vacuum leak, there is a device to introduce smoke in the vacuum lines and then one looks for the smoke escaping from the leak.

All the hints you have seen are typical locations where each member has had their problem.

Salim

matts6887

Well a odd thing is the cel light turned off when I got back in the car a little bit ago but even though the light no longer is on I know for a fact the code that popped still has to be in the ecu memory which means something is on its last legs and is on the way out.