I had a p1811 code with no hard shifts. My 1-2 shift was running .7 seconds. I put in a transgo shift kit and the shift time is now .15 sec. I have changed the fluid every 75K. It looks fine with no metal filings in the pan or burnt smells. It now has 225k miles on it. Although my p1811 code is gone that whirring sound like a pump at higher pressure is still there. It shifts like a dream. Several internet p4T65e guru's say the cure is an epc solenoid (also the transgo people say to change it also). My battle plan is to change the epc, and the two shift solenoids. Should I do anything else while I am there? Any suggestions would be appreciated. thanks.