Bad Evap Purge Vvalve? on 2004 Hyundai Sonata

check engine light on.
negative purge flow indicated.
hard to start after fill-up.
Do I need evap purge valve?
Where is it on engine?
Help please.

Asked by for the 2004 Hyundai Sonata
Just helped a friend fix this exact same issue on his 2004 hyundai santa fe. Replaced the purge control valve - a $39 part, even from the dealer. Had to get our hands dirty, but it took literally one single hour to replace the part. Filled it up immediately afterward and no more starting problems. Part is located directly behind the manifold - top, rear of the engine compartment - just between the engine
Had the same problem with starting my 2004 Sonata. I never received a code/check engine light - I've read the forums then I replaced both valves - at the manifold and canister (behind the left rear tire). And I still have the starting problem. I have to pump the gas for it to start, once started I take it for a freeway test then return...turn engine off then back on....seems to work fine. However, couple of hours later or the next morning....problem back again. Any help will be greatly appreciated.
3 more answers , 1 more comment
The purge valve pulses vacuum into the tank by way of the evaporative canister. If the valve doesnt seal when it is turned off, full vacuum goes to the tank when the car is running. The hard start comes from the fuel vapor in the tank after the fill up. Push gas in,stirs it up, extra vapors, too much fuel in the engine, hard start. I chased this problem for two hours on a toyota that did not have a purge code, it did have a fuel mixture is lean code due to it pulling air from the tank when idling. The owner had the same complaint about the hard start. I would recommend replacing the valve if it is bad and not eliminating it. I dont know exactly where it is on your car, suggest search" purge vsv location hyundai". It is most likely a dealer part. Good luck.
I had the exact same symptoms on my 2001 Sonata GLS: Hard Start after fill-up and Code P0441. I replaced the Purge Control Valve (behind the Engine Intake up against the firewall) and the problem is CURED!! Hooray!! Thanks to this site for the solution!! Here's what the part looks like:
Really, you need to first retrieve the code for the Check Engine Light being illuminated. here is an article that may help

What code indicated that there was negative purge flow? How did you come up with that term. There are several Evaporative Codes for your car and even more than 1 purge valve code.
For example it can be a flooded carbon canister that is preventing flow or causing improper flow, it can be a bad vent valve. If you even 'top off' your car when you fill up meaning you keep adding gas after the first or second 'click off' by the nozzle. Topping off can flood your EVAP system and set codes and stop the proper flow. My point here is to really determine what exactly is going on before your buy parts and install them.
A while ago I took off the purge cannister located behind the rear drivers side tire and behind the wheel well.

I ran a long pipe cleaner through all 4 lines and then through the cannister. I gently bumped the cannister on the ground to try to loosen any clog that may have been in the cannister due to my over filling the gas tank.

I reinstalled the 4 hoses and re-hung the purge cannister. I Went back to O'Reilys and re-set the system.

Drove the car 200 miles and then passed the Ill state emmsions test. Can now fuel the vehicle and it restarts with no problem. The light is off and everthing is back to normal.
Thank you all for all your help.

Best regards,