i have found for a long time now that when i run water down the disposal side it drains very slow it clears when i run the disposal, i see that my vent stack for that drain line is 4 feet from the drain it is the only drain on the stack. i am going to open the wall so i can do anything that is reqiured, except move the sink.

sounds like the disposal outlet is restricted or running uphill. before ripping anything up, check the visible issues, your issue is pretty sure to be there.

don't know what you're running down that disposal, but once you know that you have a drain away from the sink and disposal, that both are on the protected side of the trap, and that there is no visible plugging, try putting a bottle of good ol' liquid plumber in the disposal, let it sit a half hour, and follow up with a sink-full of water as hot as you have in the tap down that disposal mouth... with the motor running on the grinder.

if you've been grinding protein instead of veggies, that ought to fix your issue for a while. you should avoid putting meat and fat down a disposal, and always run it with cold water. same before you start the dishwasher that drains into the disposer, grind with cold water running to clear the path from any slop that came in from the last dishwasher run.

This message has been edited. Last edited by: swschrad,

when running your disposal use hot water
hot water liquifies fat and desolves it
it will also help desolve fat and grease that is in your pipes.
after using disposal, let the water run or a good minute afterwards. it helps flush the pipe out..
as far as your drain in wall. as switchrad said ck for the pipe having "fall" and not leval
if its 4 ft from the vent stack, thats your problem
if its a 1 1/2in inside diamater pipe
take the tee and pipe out and increase to 2in pvc pipe
turn out under cabinet with a elbow THEN reduce to 1 1/2 in