I have a 2.5 subaru it has a hesitation at hit of throttle then clears up I changed fuel filters,cleaned air filter and checked wiring. Anybody have any ideas on what could be the problem. Didn't want to take it in if it could be a easy fix. THANKS

Change plugs? check clocking on timing belt? Old fuel / or condensation in tank?

possible water in the fuel, poor injectors---sometimes moisture can sit "in" the injectors over the summer and the rest is.......
poor/kinked or broken map sensor hose. (i had one a while ago that two trips after a tune a guy complained of poor running and that the tune was wrong/poor. I disagreed (tunes don't change) we found that a rat had chewed a little hole in his map sensor hose!!!

Mabee to much oil on the air filter.

Thanks for the imput John I will check it out I thought about calling you since I got the motor from you but didn't want to bother you with something minor since your always busy. If I can't fix it I'll be bringing it in. THANKS

Try adjusting the throttle position sensor, which will move the blade in the throttle body. You may be gettting too much/not enough air when you open the throttle/

Moving the throttle position sensor will just move where the computer thinks the throttle is closed and wide open. In other words if moved, the computer could think the throttle is wide open when its really only 3/4 open. If you move the sensor then you have to calibrate the TPS with the computer, which involves tuning software.

Thanks for the help but nothing has worked yet I'll be at the SSSS so I'll talk to John or someone at thier booth.