Advice on fixing emission problem

[cluis89]

I have a 2001 corolla with the vin number 1NXBR12E41Z452925.

I got a check engine light and found that it had P0446 and P0448. So i went to the most trusted and reviewed mechanic in my area and they did a diagnosis and told me that I need to replace my VSV Pressure Switching Valve and the entire Charcoal Canister cause the sensor (vapor pressure sensor) on it was not working properly. He gave me a quote for the two parts $248 and $380 respectively plus some $300 for labor. Anyways I decided to see if I can find my own parts and save some money that way. The mechanic could only give me the part number his computer program spits out after he enters my vin number.

I found the canister and it has the same model number he gave me (77740N) and its $100 cheaper and a Genuine Toyota part. What I cannot find is the VSV Pressure Switching Valve (77740) which is partly cause I am not familiar with all the parts on the emission system. I found a pressure sensor that goes along with the canister and its the same price as what I was quoted just on sale but I am pretty sure that it's not the part I need.

Can someone help me out by pointing me to the right place to buy the Canister and the VSV Pressure Switching Valve?

 

[CarInOrder]

See here for the canister (also known as a "Vapor Canister"). That will give you an estimated cost (labor and part) and a link to an aftermarket part.

The valve is a little harder. Terminology can be a problem and there are a number of similarly named valves in the Emissions system, but I'll give it a shot. On your 2001 Corolla, the Charcoal Canister has a pressure switching valve attached to the canister. This can be replaced without getting a whole new canister, but the canister still needs to be removed, which is a pain. This pressure switching valve is also called the Canister Vent Valve. When you are on rockauto.com looking at the canister and vent valve, you can look at the pictures of the canister (scroll through them) to convince yourself that you see the yellow vent valve is attached to the canister.

There is also a fuel tank pressure sensor on the canister, which if faulty, would mean the whole canister would need to be replaced. But typically the canister needs to be removed to diagnose either of the above. Did they remove your canister to diagnose?

And there is yet another valve, called the Canister Purge Valve that is actually in the engine bay and is very easily replaced. If the mechanic means that valve, then you can easily replace it yourself and save some money.

That generation of Corolla is notorious for emission engine codes and you can end up replacing a number of parts (read $$) to chase them down.

 

[cluis89]

Thanks for the fast response and clearing things up.

I am sure they didn't remove the canister, which I was hoping they did since they were regarded so highly and the price to diagnose was so expensive. They recommended that replacing the two parts I mentioned would be the first steps they will take.