Item:93 legacy automatic.

what was done: idle control valve was adjusted, throttle stop screws (both) have been adjusted, and throttle position sensor has been adjusted.

Why: because when leaving idle with the ac or defroster on, 50% of the time it stumbles big time right off idle. With the ac and defroster off, it's fine or the stumble is so minimal that it's no problem.

why was everything adjusted: because the mechanic didn't know better. Highway mileage is around 24-25 and it drives fine. Car has 200k on it with no other problems. So basically I have a rough idle and stumble off idle 50% of the time when the ac or defroster are on. And all these things that should never be adjusted have been. Anyone know where I can find info on how to properly adjust these things? I know the lower stop screw on the plenum should NEVER be touched etc. I'm assuming nothing is set to proper adjustments anymore. The error codes vary depending on what is fiddled with. Usually coded dealing with improper signals sent to the various screwed up components. No codes until all this fiddling took place. Any help would be greatly appreciated. thanks

Also: i took out the idcle control valve, it moved freely, even swapped it out with another one to no avail. Wires, plugs, filters etc have all been changed...

Item:93 legacy automatic.

what was done: idle control valve was adjusted, throttle stop screws (both) have been adjusted, and throttle position sensor has been adjusted.

Why: because when leaving idle with the ac or defroster on, 50% of the time it stumbles big time right off idle. With the ac and defroster off, it's fine or the stumble is so minimal that it's no problem.

why was everything adjusted: because the mechanic didn't know better. Highway mileage is around 24-25 and it drives fine. Car has 200k on it with no other problems. So basically I have a rough idle and stumble off idle 50% of the time when the ac or defroster are on. And all these things that should never be adjusted have been. Anyone know where I can find info on how to properly adjust these things? I know the lower stop screw on the plenum should NEVER be touched etc. I'm assuming nothing is set to proper adjustments anymore. The error codes vary depending on what is fiddled with. Usually coded dealing with improper signals sent to the various screwed up components. No codes until all this fiddling took place. Any help would be greatly appreciated. thanks

Checked the MAF against a known good MAF? How about an O2 or knock sensor check?