Hyundai Repair: 2000 Hyundai Elantra - PO441, PO446, hyundai elantra, 2000 hyundai elantra

Question
My 2000 Elantra has the codes PO446 and PO441. We changed the canister close valve and the code remained. My car has problems starting after refueling but starts fine all the other times afterwards. We tried blowing through the purge valve and no air came out so it must not be stuck open. I don't want to keep buying parts if it's not going to fix the problem.  Any advice?  

Answer
I've never seen P0441 occur when the purge valve wasn't stuck open.  Although I, too, do not like to replace parts unnecessarily, I think you odds are high that replacing the purge control valve will solve your problem.

Also, be sure to clear your computer's memory after the repairs.  I believe this can be done on your car by disconnecting the battery for five seconds.  

If the lamp continues to stay on immediately after starting the car after you attempt to clear the codes, the codes weren't cleared.  Neither code P0446 nor P0441 can be set just by starting the vehicle.  They each require the engine to run for a period of time for the computer to detect the issue.  Furthermore, the check engine lamp shouldn't reilluminate until the computer detects the problem in two consecutive drive cycles.

If you don't clear the codes, it may take a week or so for the check engine lamp to go out.  Even after the lamp goes out, the codes will remain for a significantly longer time.

Here's why I think the purge control valve will solve your issue:
1.  The computer monitors whether the purge valve is open or closed via the reading of the MAP sensor.  P0441 sets if the MAP sensor reading is consistent with a purge valve state other than what's commanded.
2.  Although the description for P0446 reads something like "canister close valve stuck closed," what it really means is that the fuel tank pressure sensor senses a vacuum in the tank when none should be present.  Although there are a large number of reasons this could occur, only one of them is also consistent with the code P0441 as well, and that's a stuck open purge control valve.
3.  You have difficulty starting the car after refueling.  A stuck open purge valve provides a direct path for the fuel vapors to enter the engine.  Refueling then pushes these vapors into the engine, flooding it and making the vehicle difficult to start.  I cannot think of any other way for refueling to affect the ease of starting the vehicle.