'00 2.4L Motor Gremlins

This one seams basic, but I haven't been able to crack it yet. Working on a buddy's 2000 Sonata 2.4l w 66,756miles. He Drives roughly 250-300 miles a day (driving job). Car occasionally completely stalls out when idling (maybe 3 times in last 4k miles). hesitates when leaving a stop light/sign from idle, rpms drop then, just when its about to stall, sputters and gets going. Seamed like a fuel issue so we replaced fuel filter - no change. Changed spark plugs, ran 2 bottles Lucas fuel system cleaner through it, 1 bottle of Lucas fuel injector cleaner - no change. It always smells like gas inside after fill-up, but today it smelled strong all day. Check Engine Code says Insufficient EGR flow. Have replaced EGR & both hoses off EGR. Also had 3-step-fuel system-treatment done at NTB autocenter - no change.

In my mind this has to be fuel related... but don't fuel pumps typically go suddenly? Its been acting like this for the last 7k miles. Maybe a hole in a fuel line somewhere? Can anybody think of anything else before we replace a $200 fuel pump?

Thanks All!

UPDATE: At this point we've now changed the fuel pump, both O2 sensors, fuel pressure regulator, and I did the spray carb cleaner around the engine to check for vaccuum leaks trick. Still no change. I found a factory recall for the mass airflow sensor, so that will be the next step. MAF sensor would explain the driveablitly issues, but not the smell of fuel or stalling. This is a 49state car, so I've ruled out any California Emissions issue. What are the chances this could be the cat? In my experience thats always been more of a rotten egg odor, but maybe this cars an oddball? I'm out of ideas. Any input would be great.

Thanks

The fuel smell makes me think the charcoal filter that is part of the evaporative emissions system may be saturated with gasoline. A couple of things you can do to rule this out or confirm it.

Find the charcoal filter and disconnect the hose that goes to the fuel tank. This line normally only has gasoline vapor in it, not gasoline. If gasoline pours out you have found the problem. Be careful when you do this. There may be as much as a cup (8 ounces) of gasoline in the line.

Or, find the Purge control solenoid valve. It is the valve that is used to draw vapor from the charcoal cannister into the intake. This valve will be under the hood. My 2005 Sonata manual shows it near the EGR solenoid. If the cannister is saturated the vapor will be rich enough to cause the engine to idle rough or die. Unplug the electrical connector for the purge control solenoid and see if the problem goes away. You'll get a check engine light with the valve unplugged, but it won't affect engine operation.

This won't fix the problem, just tell you where the problem is. I had this problem on an Elantra. Took a while to figure it out. Symptoms were similar to what you described. Additional symptoms: Did not happen if the tank was less than half full. Would start about 30 miles after filling the tank. Strong gas smell after fill up, even ocassionally had a gas puddle under the car after going to the gas station.

Hope this helps, Eric