I have an 02 Legacy 2.5 with a problem I can't figure out. After it warms up, when you stomp on the gas from a dead stop, it hesitates BADLY before it takes off. The exhaust also has a rotten egg smell. Now, I bought this car wrecked at an auction and brought it back to life, but it has been sitting for the last 3 years with gas in it. I've gone through two or three tanks of gas since I made it road-worthy earlier this summer, but it has only gotten worse. I even bought a $300 OBD2 code scanner and it tells me nothing's wrong.:banghead: Does anyone have any ideas as to what might be wrong or busted? Anything would be appreciated. Thanks!

I have an 02 Legacy 2.5 with a problem I can't figure out. After it warms up, when you stomp on the gas from a dead stop, it hesitates BADLY before it takes off. The exhaust also has a rotten egg smell. Now, I bought this car wrecked at an auction and brought it back to life, but it has been sitting for the last 3 years with gas in it. I've gone through two or three tanks of gas since I made it road-worthy earlier this summer, but it has only gotten worse. I even bought a $300 OBD2 code scanner and it tells me nothing's wrong.:banghead: Does anyone have any ideas as to what might be wrong or busted? Anything would be appreciated. Thanks!

I take it you did run a good cleaner through with the gas.
I would suggest makeing sure that your vaccuum hoses are in good shape and routed properly. Check the intake manifold to see if you have a leak there. I had a volvo years ago and the vacuum hose going to the brake booster was cracked it would open when a lot of throttle was used causing the engine to torque on the mounts. Under normal load it would be fine. The rotten egg smell may not be a problem.
Hope this helps
Hans

Clean your injectors.
Test and adjust the TPS Throttle Position Sensor

Sounds like a Oxygen sensor on the way out, which has caused the Cat to go bad (rotten egg smell). is there a CEL, or is there even a bulb in that spot?

Try the cheaper general maintenance stuff first though. Air filter, sparkplugs and wires, fuel filter...