Toyota Repair: REPAIR PROBLEM, toyota camry v6, purge valve

Question
I have two problems with a '99 manual Toyota Camry  V6. The Camry having a burning smell and losing power going up a steep hill.  I had thecomplete clutch replaced with an aftermarket OEM clutch 4 years ago. Does it mater whether you use the Toyota original clutch or can you use an aftermarket clutch?
It is also throwing off two codes P0041 and P0046. One mechanic read the codes and told me that I needed a purge valve on the engine and a 2 way valve on the cannister replaced. When I called Toyota for the prices they told me the I would have to purchase a cannister with the 2 way valve that it doesn't come separately. When I asked the mechanic how he could get the 2WV w/o purchasing the canister, He said that he has a special purchase account with Toyota so that this is possible. Could he be putting in a used Toyota part from the junkyard and just telling me that it is a new part? Another mechanic told me that I should have the car checked out for a possibility that a  spider in the exhaust system could be throwing off the codes? Is this a real possibility if I drive the car every day?

Answer
Hello, it is ok in most cases to use an aftermarket clutch but quality of the parts can be a concern and it should last more than four years, I don't really know if that's even the loss of power and the smell, if the engine seems to increase in speed with no increase in road speed then it could very well be the case.
I would recommend following the dealer's advice and replace the canister assembly with one from the dealer, these are emission control codes relating to the fuel evap recovery system and has nothing to do with a "spider in the exhaust" nonsense.