IM trying to buy a car and the guy said the only.

Just to let you know a epc(electronic pressure control)solenoid is part of the transmission and is not a major issue to be concerned with.I recently replaced a solenoid on a vehicle with the same issue. Here is some information that may help you.

(The electronic pressure control (EPC) transmission switch controls the EPC unit, which regulates the hydraulic pressure in your automatic transmission. This regulation allows the transmission to change its resistance levels when the engine begins to work harder. With greater pressure, the engine has to work harder to shift the gears, which prevents it from running up against its redline. Conversely, when the engine is under load, the pressure is reduced by the EPC so the engine works less on having to moving the transmission gears and can use its energy to move the load.)

Not a hard job however without mechanical experience I suggest you get it repaired by a professional. Part runs you around $40 bucks and will be $0 labor of coarse if you DIY. Prices of labor varies depending on what shop you choose so take it to a professional if you are unsure how to replace solenoid yourself.A bad epc solenoid is not a bad transmission. I hope this helps(7 years experience)